ACS Publications. Most Trusted. Most Cited. Most Read
My Activity
CONTENT TYPES

Figure 1Loading Img
RETURN TO ISSUEPREVResearch ArticleNEXT

Traveling Wave Rotary Micromotor Based on a Photomechanical Response in Liquid Crystal Polymer Networks

  • Klaudia Dradrach
    Klaudia Dradrach
    Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
  • Mikołaj Rogóż
    Mikołaj Rogóż
    Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
  • Przemysław Grabowski
    Przemysław Grabowski
    Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
  • Chen Xuan
    Chen Xuan
    Department of Mathematical Sciences, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Rd, Suzhou 215123, China
    More by Chen Xuan
  • Rafał Węgłowski
    Rafał Węgłowski
    Institute of Applied Physics, Military University of Technology, ul. Kaliskiego 2, 01-476 Warsaw, Poland
  • Jolanta Konieczkowska
    Jolanta Konieczkowska
    Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Skłodowskiej 34, 41-819 Zabrze, Poland
  • Ewa Schab-Balcerzak
    Ewa Schab-Balcerzak
    Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Skłodowskiej 34, 41-819 Zabrze, Poland
  • Wiktor Piecek
    Wiktor Piecek
    Institute of Applied Physics, Military University of Technology, ul. Kaliskiego 2, 01-476 Warsaw, Poland
  • , and 
  • Piotr Wasylczyk*
    Piotr Wasylczyk
    Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
    *E-mail: [email protected]
Cite this: ACS Appl. Mater. Interfaces 2020, 12, 7, 8681–8686
Publication Date (Web):January 29, 2020
https://doi.org/10.1021/acsami.9b20309

Copyright © 2020 American Chemical Society. This publication is licensed under CC-BY.

  • Open Access

Article Views

3064

Altmetric

-

Citations

LEARN ABOUT THESE METRICS
PDF (2 MB)
Supporting Info (7)»

Abstract

The photomechanical response of liquid crystal polymer networks (LCNs) can be used to directly convert light energy into different forms of mechanical energy. In this study, we demonstrate how a traveling deformation, induced in a liquid crystal polymer ring by a spatially modulated laser beam, can be used to drive the ring (the rotor) to rotate around a stationary element (the stator), thus forming a light-powered micromotor. The photomechanical response of the polymer film is modeled numerically, different LCN molecular configurations are studied, and the performance of a 5.5 mm diameter motor is characterized.

Introduction

ARTICLE SECTIONS
Jump To

“Can light drive a motor?” was the opening question asked in the seminal paper of Ikeda et al. (1) In most power systems, light (solar) energy is converted either to directly useful heat (in solar thermal collectors) or to electric energy (in solar cells) to be used or stored. Converting light energy directly into mechanical energy is more challenging, although several approaches have been demonstrated at different scales, from the molecular to macroscopic. (2−4) An attractive aspect here is the possibility of remotely powering mechanical devices with light (delivered either via free space propagation or through optical fibers), where using electrical conductors and/or currents is not feasible.
In 1975, De Gennes proposed the idea of anisotropic cross-linked polymer networks with the orientational order of nematogenic monomers, (5) thus initiating research efforts to fabricate, understand, and use ordered, responsive polymers, in particular liquid crystal networks (LCNs). LCNs are solid polymers with a well-defined alignment of molecules (i.e., with a well-defined director of the molecular blocks), similar to that observed in liquid crystals, with a moderate to densely cross-linked network architecture. With partially anisotropic properties of the LC phase, LCNs have unique anisotropic properties, including the elastic ones. They may exhibit very large, reversible deformations in response to the external stimuli: heating, (6) light triggering photochemical reactions, (7,8) light inducing photothermal heating, (6,9,10) external electric field, (11,12) or the presence of solvent. (13) Cross-linked chains of molecules undergo the order–disorder (anisotropic–isotropic) transition and, as a result, the material deforms in a way determined by the spatial distribution of the director and the spatio-temporal distribution of the stimulus, for example, light. Additional mechanical actuation modes may be available with light spectral (14,15) or polarization (16,17) degrees of freedom. Light-powered LCE elements (18,19) have been used as micro-actuators in various configurations (20,21) (cf. (22) for a recent review on light-driven LC materials, (23) on LCN and LC elastomers (LCE) soft robots and (24) on LCN and LCE actuators).
A light-driven motor utilizing the contraction (expansion) of an azobenzene-containing LCE laminated with a polyethylene film upon UV (visible) light irradiation was reported by Yamada et al. (1) The motor presented by Geng et al. (25) used a looped stripe of a hydroxypropylcellulose film that deformed under humid air to drive a rotating element. The LCE rod, described in ref (26) can roll with either a light beam or a heated surface as the energy source. Recently, different modes of deformations in LCE tubes and helical ribbons have been demonstrated as drives for centimeter-scale light-powered rolling vehicles. (27)
In this paper, we present a rotary micromotor, inspired by the ring-shape piezoelectric ultrasonic motors (USMs), often used in the auto-focusing mechanism of compound lenses, for example, in SLR cameras. USMs of this type have a piezoelectric ring actuator in which a traveling mechanical flexural wave is electrically generated and it drives a rotor via friction coupling (28−30) (Figure 1). Our micromotor has a ring-shaped rotor made of an LCN film with a radial or azimuthal director orientation of the director at each surface. An all-optical method employing photo-oriented azopolyimide layers for generating arbitrary two-dimensional director distribution in the LCN film was used for the first time. The principle of a photo-induced traveling deformation in an LCN element, combined with friction coupling that earlier allowed us to demonstrate a life-size crawling caterpillar soft robot, (31) now also proved to be well suited for the rotary micromotor design. In the USM-inspired micromotor, the traveling deformation is generated in the ring rotor by the photomechanical response due to light absorbed from a spatially modulated (rotated) laser beam.

Figure 1

Figure 1. (a) Dynamic deformation induced in the stator (orange) interacts via friction forces with the rotor ring (blue). (b) Traveling deformation of the liquid crystalline polymer ring (orange), induced by a spatially modulated laser beam, interacts with the stationary substrate (blue), and thus, the ring rotates around the vertical axis. (c) Photothermally induced deformation traveling along the rotor circumference (time t1 < t2 < t3 < t4, VTW—velocity of the traveling wave) results in each point on the surface following a regular orbit (grey dashed line). When the rotor comes in contact with a stationary substrate, the static friction force FSF acts on the rotor and sets it in motion. The white scale bar is 2 mm long. Panel (a) is adapted from. (32)

Experimental Section

ARTICLE SECTIONS
Jump To

Liquid Crystal Polymer Network Film

The liquid crystal cross-linked polymer mixture is based on commercially available compounds and contains 78 wt % of the LC monomer (Synthon), 20 wt % of the LC cross-linker (Synthon), 1 wt % of the photoinitiator (Irgacure 369, Sigma-Aldrich), and 1 wt % of the dye (Disperse Red 1, Sigma-Aldrich), as reported in ref (31). The orange dye provides efficient green laser light absorption. All the compounds were melted and stirred on a hot plate in a glass flask at 80 °C.
To prepare LCN films with a proper molecular orientation, a photopatterning technology was used. Glass slides were spin-coated with a newly synthesized photoalignment azopolyimide (PI) solution (∼1%) in N-methyl-2-pyrrolidone, dried, and heated at 130 °C for 2.5 h to evaporate the solvent. Chemical structure and characterization of the PI are presented in the Supporting Information. To create radial or azimuthal distribution of the director in the LCN film, the polyimide orienting layers were exposed to linearly polarize UV light with wavelengths in the 345–380 nm band (Hamamatsu LC8 Xe-Hg UV lamp with a Glan-Taylor prism polarizer) with 15 mW/cm2 intensity at the glass plane for 1 h. A wedge-shaped aperture was used in the UV beam, and the substrate was rotated continuously during the exposure. Two substrates were assembled to form a 25 μm cell with the azimuthal–azimuthal (A–A) or azimuthal–radial orientation (A–R, also known as circular twisted nematic; (33)  Figure 2). The cell was filled with the molten LCN mixture on a hot plate at 80 °C and cooled slowly (2 °C/min) to 40 °C. The LCN layer, with the director distribution defined by the LCE interaction with the orienting layers, was then polymerized with 380 nm UV LEDs for 20 min at 40 °C. After being dipped in water at room temperature, the cell was wedged open, the LCN film was removed and the rotor ring (5.5 mm outer diameter, 1.3 mm inner diameter) was cut with a razor blade.

Figure 2

Figure 2. (a) Cross-linked polymer chains (yellow) arranged in one direction in an LC polymer network stripe deform locally because of increased temperature. With efficient light-absorbing dye, the heating can be induced by light absorption from a laser beam. (b) LC monomer, cross-linker, dye (Disperse Red 1) and photoinitiator used in the LCN. The coloring is consistent with panel (a). (c,d) Orientation of the molecular director n at the top and bottom surfaces of the cells used for preparing the LCN films: azimuthal (A) and radial (R). Two types of LCN films were prepared: A–A and A–R. Blue rings present how the micromotor rotor was cut from the film. (e,f) A–A and A–R cells filled with the LCN mixture, observed with a polarizing optical microscope (the arrows indicate the polarizer and analyzer orientation). The white scale bars in the photos are 10 mm long.

Differential scanning calorimetry (DSC) of the LCN film was used to determine the glass transition temperature (Tg) and the LC phase transitions (Figure S2 in the Supporting Information). The material has Tg of 11 and 7 °C upon heating and cooling, respectively, and the isotropization temperatures of 120 and 95 °C upon heating and cooling, respectively. The dynamic mechanical thermal analysis (DMTA) reveals the α relaxation corresponding to the glass–rubber transition (Figure S3 in the Supporting Information). The loss modulus peak and the inflection point of the storage modulus drop were observed at 17 °C, close to the values obtained from DSC.

Experimental Setup

A CW 532 nm laser (Verdi V-5, Coherent, 5.0 W maximum power, Gaussian beam full width at half maximum equal 1.9 mm at the LCN ring plane) was used to power the micromotor. The beam was steered with a rotating mirror to follow a 1.7 mm radius circular path (Figure 3a). The LCN was in contact with a sandpaper substrate (2000 grit) and could rotate freely around a stationary axis (a glass tube or steel rod). In our earlier works on light-driven microrobots based on photomechanically induced traveling wave, (31) we tested several substrates, including glass, paper, and different sandpapers, with different tribological properties. For the current experiments, we have chosen the substrate that proved to perform best in terms of the friction coupling and thus the motor performance. The static friction coefficient between the rotor and the substrate μ = 1.19 ± 0.04 was measured by pulling a flat LCN film over the substrate and recording the minimum force (Lutron FG-5000A force gauge) needed to set it in motion under a given load. A video camera (DLT Cam PRO 5 MP, 30 frames/s) was used to record the ring deformation and the motor rotation. A paint mark on the LCN ring edge was used to track and analyze the motion of the micromotor rotor. An IR imaging camera (Fluke Ti400) was used to record the time-dependent temperature distribution in the rotor.

Figure 3

Figure 3. (a) Schematic of the experimental setup. The laser beam is reflected from a rotating mirror and sweeps around the LCN rotor ring. (b) Static LCN ring deformation due to the photomechanical response: yellow and red (computer-added colors) areas are images of the ring without and with the laser on, respectively. The white scale bar in the photo is 1 mm long. (c) LCN micromotor speed varies with the increasing P/f ratio, where P is the laser power and f is the mirror rotation frequency. Rotor with A–R orientation. (d) Same as (c) for the rotor with A–A orientation. (e) Snapshots of the numerical simulation of the traveling LCN ring deformations for the A–R orientation. (f) Same as (e) for the A–A orientation.

Numerical Simulations of the Photothermal Deformation

Finite element numerical simulations of the rotor ring deformation dynamics were performed in COMSOL Multiphysics using the Solid Mechanics Module. In the model, laser illumination locally raises the temperature of the LCN ring and thus reduces the liquid crystal order, causing the ring to contract along the local director, and at the same time to swell in the perpendicular dimensions. The photomechanical deformation is modeled by introducing a local photo-strain tensor εph(x) = εph [(1 + ν) n × n – νI] into the stress (σ)–strain (ε) constitutive relation: σ(x) = C:[ε(x) – εph(x)], where C is the stiffness tensor of the ring, εph(x) is the photo-induced strain along the director n and the Poisson ratio of the ring ν = 0.5. The simulation results are presented in Figure 3e,f and in the Supporting Information Movies 3 and 4 for the two molecular orientations in the LCN rotor ring. The simulations indicate that the light-induced stress in the rotor ring indeed results in a traveling deformation, following the spatially modulated laser beam. The model we use is able to predict the qualitative dynamics of the circular rotor with different molecular orientations—the exact shape of the deformation in the experiments is more complex, as there are other factors involved, not accounted for in the model: residual stress from the LCN film fabrication, (anisotropic) thermal expansion, and nonlinear relation between the deformation and the light intensity (becoming more important for the light intensities where the photomechanical response saturates).

Results and Discussion

ARTICLE SECTIONS
Jump To

Light-Powered Deformation and the Traveling Wave Micromotor Rotary Motion

In our LCN micromotor, the rotor deformation is realized by photoheating (34)—laser light absorption (25 μm film absorbs ∼90% of the incident green light) which induces a reversible nematic–isotropic phase transition in the liquid crystal polymer network. As a result, an LCN stripe with homeotropic alignment locally contracts (expands) in the direction parallel (perpendicular) to the molecular alignment (director) and as a result the initially near-flat ring deforms into a complex three-dimensional shape (35−37) (Figure 3b). More complex, patterned alignments may provide more sophisticated shape-reconfigurable surfaces from flat LCE or LCN sheets, (38) in particular the azimuthal–azimuthal (A–A) orientation in a flat film results in a conical deformation, whereas radial (R–R) orientation makes the film deform into a saddle. (33,39)
With the laser power and the scanning speed adjusted properly, a traveling macroscopic deformation of the LCN is observed, which results in a rotary motion of the ring via friction coupling with the substrate (Supporting Information Movies 1 and 2). The LCN ring deformation resembles the traveling wave of an ultrasonic ring motor. The light-driven motor works in the regime where the laser-induced polymer film temperature increases only locally and, as the light beam moves away, it decreases with a time constant of the order of tens to hundreds of milliseconds, mainly due to conductive heat transfer to the surrounding air. (31,34) As a result, after many scan cycles (rotations), the average temperature of the rotor remains close to the room temperature, and there is a significant difference in the temperature between the illuminated area (spot) and the surrounding film—Supporting Information Movie 5 shows the temperature distribution in the moving rotor, visualized with an IR camera.
Depending on the molecular alignment in the LCN ring, the actuation in response to the local temperature increase varies. For the azimuthal (A–A) alignment, the ring contracts circularly and swells along the radius and in thickness. The A–R film bends locally, within a sector of around 70°, toward the substrate (sandpaper) and the neighboring sectors bend up and lose contact with the substrate (Figure 3b). If the laser scanning speed is slow enough, the ring deformations follow the laser beam around the ring—Movies 1 and 2 in the Supporting Information.
The micromotor rotation speed depends on the light energy absorbed in the material within a given time that is proportional to P/f, where P is the laser power and f is the mirror rotation frequency (in turns/s). (34) For a constant laser power, the motor speed increases with the increasing beam scanning speed, up to a point where the time constant governing the photomechanical response in the LCN is too large to allow for enough heat to accumulate and produce a significant ring deformation (Figure 3c). For low laser powers, the film reaches the regime where no significant deformation is present, while at the other extreme of high laser powers, material damage results. For the A–R alignment, there is no visible difference between the configurations with the A or R side facing up (toward the laser). The micromotor with the A–R LCN ring rotates around ten times faster than the one with the A–A LCN rotor (Figure 3d)—the conical rotor deformation induced in the latter case is not as efficient in the friction coupling to the stator (compare also the trajectory analysis below).
Movie 6 in the Supporting Information demonstrates how the rotor can be friction-coupled to an external axis (made of a 2.1 mg paper tube, compared to a rotor mass of 0.8 mg) to deliver a usable mechanical power output.
Tracking one point at the edge of the LCN rotor offers some insight into the rotor ring deformation and the micromotor kinematics. For the A–A oriented film, the point at the rotor circumference follows a spiral trajectory, reversing after each step, and at the same time, the steps are more regular and shorter . In the case of the A–R orientation, such a point follows a sine-like trajectory, with the motor segments moving in large steps after each laser beam sweep. (Figure 4). The A–A motor needs 172 s to perform a 90° rotation with the average angular frequency ω = 0.009 rad/s while the A–R motor makes a full 360° rotation in 64 s with average ω = 0.098 rad/s. The micromotor efficiency, defined as the ratio between the motor revolutions per minute to the laser beam rotations per minute, is between 0.4 and 0.6% for the A–A orientation and between 4.7 and 8.3% for the A–R orientation.

Figure 4

Figure 4. Measured trajectory of one point at the LCN ring edge for two film orientations: A–A (a,c) and A–R (b,d). The white scale bars are 1 mm long. (a,b) Measured (tracked) position of the point at the rotor circumference. (c,d) x and y coordinates of the points in (a,b) vs time.

Conclusions

ARTICLE SECTIONS
Jump To

Our results show that dynamic photothermally induced deformations in liquid crystal elastomer films can drive rotary motion on a small (millimeter) scale. We harnessed the time-dependent mechanical response of a properly oriented LCN ring, combined with friction coupling to power a rotary micromotor resembling ultrasonic piezoelectric ring motors. In such an elastomer film rotor, the molecular alignment defines the deformation topology, while the photomechanical response time constant, the absorbed light energy and the laser beam scanning speed determine the motor speed. As the A–A orientation offers a more regular motion, it may be more suitable for applications where regulation is of primary importance, rather than the net rotation speed. The irregularities in the rotor with the A–R orientation most likely originate from a combination of the nonlinear dependence of the photomechanical response to the light intensity, anisotropic thermal expansion of the rotor, and the residual stress in the polymer film.
Most of the polymer light-driven motors and drives presented to date rely on shifting the center of the mass position by photo-induced deformation in a contacting, bending, or twisting element(s)—as a result, the system finds a new, different equilibrium position and this generates motion. Our motor uses the friction coupling between two elements to generate rotary motion and as such is, in principle, independent from gravity.
Despite the low speed and poor efficiency, the LCN micromotor presents a new approach to small-scale mechanics and micro-scale drives and opens up a new class of light-powered, friction-coupled actuators, for example, based on the inchworm drive principle. With the current LCN technology, also using laser photolithography, it can be directly scaled down to sub-millimeter dimensions (40,41) and may find applications in areas where devices must be powered and controlled remotely and/or without electrical currents being involved.

Supporting Information

ARTICLE SECTIONS
Jump To

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.9b20309.

  • Chemical structure and characterization of the PI, DSC, and DMTA characterization of the LCN films (PDF)

  • Rotating micro-motor with A–R orientation (MP4)

  • Rotating micro-motor with A–A orientation (MP4)

  • Numerical simulation results for the photomechanical response of an LCN rotor ring with A–R orientation (MP4)

  • Numerical simulation results for the photomechanical response of an LCN rotor ring with A–A orientation (MP4)

  • Temperature distribution in the rotating micro-motor (MP4)

  • Ring micro-motor turning a tube on the axis (MP4)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Author Information

ARTICLE SECTIONS
Jump To

  • Corresponding Author
  • Authors
    • Klaudia Dradrach - Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
    • Mikołaj Rogóż - Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
    • Przemysław Grabowski - Photonic Nanostructure Facility, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
    • Chen Xuan - Department of Mathematical Sciences, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Rd, Suzhou 215123, China
    • Rafał Węgłowski - Institute of Applied Physics, Military University of Technology, ul. Kaliskiego 2, 01-476 Warsaw, Poland
    • Jolanta Konieczkowska - Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Skłodowskiej 34, 41-819 Zabrze, PolandOrcidhttp://orcid.org/0000-0001-8096-2661
    • Ewa Schab-Balcerzak - Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Skłodowskiej 34, 41-819 Zabrze, Poland
    • Wiktor Piecek - Institute of Applied Physics, Military University of Technology, ul. Kaliskiego 2, 01-476 Warsaw, Poland
  • Notes
    The authors declare no competing financial interest.

Acknowledgments

ARTICLE SECTIONS
Jump To

This work was generously supported by the National Science Center (Poland) with grant No. 2018/29/B/ST7/00192, by the Polish Ministry of Science and Higher Education (MNiSW) “Diamentowy Grant” project No. DI2016 015046, and by the Ministry of National Defense (Poland) Program—Research Grant MUT Project 13-995. C.X. acknowledges support of the Key Program Special Fund (KSF) KSF-E-53 at XJTLU.

References

ARTICLE SECTIONS
Jump To

This article references 41 other publications.

  1. 1
    Yamada, M.; Kondo, M.; Mamiya, J.-i.; Yu, Y.; Kinoshita, M.; Barrett, C. J.; Ikeda, T. Photomobile Polymer Materials: Towards Light-Driven Plastic Motors. Angew. Chem., Int. Ed. 2008, 47, 49864988,  DOI: 10.1002/anie.200800760
  2. 2
    Wang, H.; Pumera, M. Fabrication of Micro/Nanoscale Motors. Chem. Rev. 2015, 115, 87048735,  DOI: 10.1021/acs.chemrev.5b00047
  3. 3
    Xu, L.; Mou, F.; Gong, H.; Luo, M.; Guan, J. Light-Driven Micro/Nanomotors: From Fundamentals to Applications. Chem. Soc. Rev. 2017, 46, 69056926,  DOI: 10.1039/c7cs00516d
  4. 4
    Chen, H.; Zhao, Q.; Du, X. Light-Powered Micro/Nanomotors. Micromachines 2018, 9, 41,  DOI: 10.3390/mi9020041
  5. 5
    Degennes, P. G. One Type of Nematic Polymers. C. R. Seances Acad. Sci., Ser. B 1975, 281, 101103
  6. 6
    Sawa, Y.; Urayama, K.; Takigawa, T.; DeSimone, A.; Teresi, L. Thermally Driven Giant Bending of Liquid Crystal Elastomer Films with Hybrid Alignment. Macromolecules 2010, 43, 43624369,  DOI: 10.1021/ma1003979
  7. 7
    Yu, Y.; Nakano, M.; Ikeda, T. Directed Bending of a Polymer Film by Light - Miniaturizing a Simple Photomechanical System Could Expand its Range of Applications. Nature 2003, 425, 145,  DOI: 10.1038/425145a
  8. 8
    Braun, L.; Linder, T.; Hessberger, T.; Zentel, R. Influence of a Crosslinker Containing an Azo Group on the Actuation Properties of a Photoactuating LCE System. Polymers 2016, 8, 435,  DOI: 10.3390/polym8120435
  9. 9
    Pevnyi, M.; Moreira-Fontana, M.; Richards, G.; Zheng, X.; Palffy-Muhoray, P. Studies of Photo-Thermal Deformations of Liquid Crystal Elastomers Under Local Illumination. Mol. Cryst. Liq. Cryst. 2017, 647, 228234,  DOI: 10.1080/15421406.2017.1289599
  10. 10
    Yang, H.; Buguin, A.; Taulemesse, J.-M.; Kaneko, K.; Méry, S.; Bergeret, A.; Keller, P. Micron-Sized Main-Chain Liquid Crystalline Elastomer Actuators with Ultralarge Amplitude Contractions. J. Am. Chem. Soc. 2009, 131, 1500015004,  DOI: 10.1021/ja905363f
  11. 11
    Urayama, K.; Honda, S.; Takigawa, T. Electrooptical Effects with Anisotropic Deformation in Nematic Gels. Macromolecules 2005, 38, 35743576,  DOI: 10.1021/ma0503054
  12. 12
    Spillmann, C. M.; Ratna, B. R.; Naciri, J. Anisotropic Actuation in Electroclinic Liquid Crystal Elastomers. Appl. Phys. Lett. 2007, 90, 021911,  DOI: 10.1063/1.2420780
  13. 13
    Urayama, K. Selected Issues in Liquid Crystal Elastomers and Gels. Macromolecules 2007, 40, 22772288,  DOI: 10.1021/ma0623688
  14. 14
    Kumar, K.; Knie, C.; Bleger, D.; Peletier, M. A.; Friedrich, H.; Hecht, S.; Broer, D. J.; Debije, M. G.; Schenning, A. A Chaotic Self-Oscillating Sunlight-Driven Polymer Actuator. Nat. Commun. 2016, 7, 11975,  DOI: 10.1038/ncomms11975
  15. 15
    Cheng, Z.; Wang, T.; Li, X.; Zhang, Y.; Yu, H. NIR-Vis-UV Light-Responsive Actuator Films of Polymer-Dispersed Liquid Crystal/Graphene Oxide Nanocomposites. ACS Appl. Mater. Interfaces 2015, 7, 2749427501,  DOI: 10.1021/acsami.5b09676
  16. 16
    Tabiryan, N.; Serak, S.; Dai, X.-M.; Bunning, T. Polymer Film with Optically Controlled Form and Actuation. Opt. Express 2005, 13, 74427448,  DOI: 10.1364/opex.13.007442
  17. 17
    Martella, D.; Nocentini, S.; Micheletti, F.; Wiersma, D. S.; Parmeggiani, C. Polarization-Dependent Deformation in Light Responsive Polymers Doped by Dichroic Dyes. Soft Matter 2019, 15, 13121318,  DOI: 10.1039/c8sm01954a
  18. 18
    Gelebart, A. H.; Jan Mulder, D.; Varga, M.; Konya, A.; Vantomme, G.; Meijer, E. W.; Selinger, R. L. B.; Broer, D. J. Making Waves in a Photoactive Polymer Film. Nature 2017, 546, 632636,  DOI: 10.1038/nature22987
  19. 19
    Liu, X.; Kim, S.-K.; Wang, X. Thermomechanical Liquid Crystalline Elastomer Capillaries with Biomimetic Peristaltic Crawling Function. J. Mater. Chem. B 2016, 4, 72937302,  DOI: 10.1039/c6tb02372j
  20. 20
    Ma, S.; Li, X.; Huang, S.; Hu, J.; Yu, H. A Light-Activated Polymer Composite Enables On-Demand Photocontrolled Motion: Transportation at the Liquid/Air Interface. Angew. Chem., Int. Ed. 2019, 58, 26552659,  DOI: 10.1002/anie.201811808
  21. 21
    Cheng, Z.; Ma, S.; Zhang, Y.; Huang, S.; Chen, Y.; Yu, H. Photomechanical Motion of Liquid-Crystalline Fibers Bending Away from a Light Source. Macromolecules 2017, 50, 83178324,  DOI: 10.1021/acs.macromol.7b01741
  22. 22
    Bisoyi, H. K.; Li, Q. Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications. Chem. Rev. 2016, 116, 1508915166,  DOI: 10.1021/acs.chemrev.6b00415
  23. 23
    Zeng, H.; Wasylczyk, P.; Wiersma, D. S.; Priimagi, A. Light Robots: Bridging the Gap between Microrobotics and Photomechanics in Soft Materials. Adv. Mater. 2018, 30, 1703554,  DOI: 10.1002/adma.201703554
  24. 24
    Ge, F.; Zhao, Y. Microstructured Actuation of Liquid Crystal Polymer Networks. Adv. Funct. Mater. 2020, 30, 1901890,  DOI: 10.1002/adfm.201901890
  25. 25
    Geng, Y.; Almeida, P. L.; Fernandes, S. N.; Cheng, C.; Palffy-Muhoray, P.; Godinho, M. H. A Cellulose Liquid Crystal Motor: A Steam Engine of the Second Kind. Sci. Rep. 2013, 3, 1028,  DOI: 10.1038/srep01028
  26. 26
    Ahn, C.; Li, K.; Cai, S. Light or Thermally Powered Autonomous Rolling of an Elastomer Rod. ACS Appl. Mater. Interfaces 2018, 10, 2568925696,  DOI: 10.1021/acsami.8b07563
  27. 27
    Lu, X.; Guo, S.; Tong, X.; Xia, H.; Zhao, Y. Tunable Photocontrolled Motions Using Stored Strain Energy in Malleable Azobenzene Liquid Crystalline Polymer Actuators. Adv. Mater. 2017, 29, 1606467,  DOI: 10.1002/adma.201606467
  28. 28
    Morita, T. Miniature Piezoelectric Motors. Sens. Actuators, A 2003, 103, 291300,  DOI: 10.1016/s0924-4247(02)00405-3
  29. 29
    Oh, J.-H.; Jung, H.-E.; Lee, J.-s.; Lim, K.-J.; Kim, H.-H.; Ryu, B.-H.; Park, D.-H. Design and Performances of High Torque Ultrasonic Motor for Application of Automobile. J. Electroceram. 2009, 22, 150155,  DOI: 10.1007/s10832-008-9434-1
  30. 30
    Spanner, K.; Koc, B. Piezoelectric Motors, an Overview. Actuators 2016, 5, 6,  DOI: 10.3390/act5010006
  31. 31
    Rogóż, M.; Zeng, H.; Xuan, C.; Wiersma, D. S.; Wasylczyk, P. Light-Driven Soft Robot Mimics Caterpillar Locomotion in Natural Scale. Adv. Opt. Mater. 2016, 4, 16891694,  DOI: 10.1002/adom.201600503
  32. 32
    Bar-Cohen, Y.; Bao, X. Q.; Grandia, W. Rotary Ultrasonic Motors Actuated by Traveling Flexural Waves. Proc. SPIE 1999, 3668, 698704
  33. 33
    de Haan, L. T.; Sanchez-Somolinos, C.; Bastiaansen, C. M. W.; Schenning, A.; Broer, D. J. Engineering of Complex Order and the Macroscopic Deformation of Liquid Crystal Polymer Networks. Angew. Chem., Int. Ed. 2012, 51, 1246912472,  DOI: 10.1002/anie.201205964
  34. 34
    Rogóż, M.; Dradrach, K.; Xuan, C.; Wasylczyk, P. A Millimeter-Scale Snail Robot Based on a Light-Powered Liquid Crystal Elastomer Continuous Actuator. Macromol. Rapid Commun. 2019, 40, 1900279,  DOI: 10.1002/marc.201900279
  35. 35
    Küpfer, J.; Finkelmann, H. Nematic Liquid Single-Crystal Elastomers. Makromol. Chem., Rapid Commun. 1991, 12, 717726,  DOI: 10.1002/marc.1991.030121211
  36. 36
    Finkelmann, H.; Nishikawa, E.; Pereira, G. G.; Warner, M. A New Opto-Mechanical Effect in Solids. Phys. Rev. Lett. 2001, 87, 015501,  DOI: 10.1103/physrevlett.87.015501
  37. 37
    Li, M.-H.; Keller, P. Artificial Muscles Based on Liquid Crystal Elastomers. Philos. Trans. R. Soc., A 2006, 364, 27632777,  DOI: 10.1098/rsta.2006.1853
  38. 38
    McConney, M. E.; Martinez, A.; Tondiglia, V. P.; Lee, K. M.; Langley, D.; Smalyukh, I. I.; White, T. J. Topography from Topology: Photoinduced Surface Features Generated in Liquid Crystal Polymer Networks. Adv. Mater. 2013, 25, 58805885,  DOI: 10.1002/adma.201301891
  39. 39
    Ahn, S.-k.; Ware, T. H.; Lee, K. M.; Tondiglia, V. P.; White, T. J. Photoinduced Topographical Feature Development in Blueprinted Azobenzene-Functionalized Liquid Crystalline Elastomers. Adv. Funct. Mater. 2016, 26, 58195826,  DOI: 10.1002/adfm.201601090
  40. 40
    Zeng, H.; Martella, D.; Wasylczyk, P.; Cerretti, G.; Lavocat, J.-C. G.; Ho, C.-H.; Parmeggiani, C.; Wiersma, D. S. High-Resolution 3D Direct Laser Writing for Liquid Crystalline Elastomer Microstructures. Adv. Mater. 2014, 26, 23192322,  DOI: 10.1002/adma.201305008
  41. 41
    Zeng, H.; Wasylczyk, P.; Parmeggiani, C.; Martella, D.; Burresi, M.; Wiersma, D. S. Light-Fueled Microscopic Walkers. Adv. Mater. 2015, 27, 38833887,  DOI: 10.1002/adma.201501446

Cited By

ARTICLE SECTIONS
Jump To

This article is cited by 18 publications.

  1. Boris Kichatov, Alexey Korshunov, Vladimir Sudakov, Vladimir Gubernov, Alexandr Golubkov, Alexey Kiverin. Superfast Active Droplets as Micromotors for Locomotion of Passive Droplets and Intensification of Mixing. ACS Applied Materials & Interfaces 2021, 13 (32) , 38877-38885. https://doi.org/10.1021/acsami.1c09912
  2. Jolanta Konieczkowska, Dorota Neugebauer, Anna Kozanecka-Szmigiel, Aleksy Mazur, Sonia Kotowicz, Ewa Schab-Balcerzak. Photoresponse of new azo pyridine functionalized poly(2-hydroxyethyl methacrylate-co-methyl methacrylate). Scientific Reports 2024, 14 (1) https://doi.org/10.1038/s41598-024-59704-1
  3. Dorota Węgłowska, Yingge Chen, François Ladouceur, Leonardo Silvestri, Rafał Węgłowski, Michał Czerwiński. Single ferroelectric liquid crystal compounds targeted for optical voltage sensing. Journal of Molecular Liquids 2024, 399 , 124454. https://doi.org/10.1016/j.molliq.2024.124454
  4. Frank Sun, Rocco T. Shasho, Michael Crescimanno, Nathan J. Dawson. All-Optical Method of Determining Laser Power from the Photomechanical Effect. Applied Sciences 2022, 12 (21) , 10708. https://doi.org/10.3390/app122110708
  5. Mikołaj Rogóż, Zofia Dziekan, Klaudia Dradrach, Michał Zmyślony, Paweł Nałęcz-Jawecki, Przemysław Grabowski, Bartosz Fabjanowicz, Magdalena Podgórska, Anna Kudzia, Piotr Wasylczyk. From Light-Powered Motors, to Micro-Grippers, to Crawling Caterpillars, Snails and Beyond—Light-Responsive Oriented Polymers in Action. Materials 2022, 15 (22) , 8214. https://doi.org/10.3390/ma15228214
  6. Alissa Potekhina, Changhai Wang. Liquid Crystal Elastomer Based Thermal Microactuators and Photothermal Microgrippers Using Lateral Bending Beams. Advanced Materials Technologies 2022, 7 (10) https://doi.org/10.1002/admt.202101732
  7. Juzhong Zhang, Dandan Sun, Bin Zhang, Qingqing Sun, Yang Zhang, Shuiren Liu, Yaming Wang, Chuntai Liu, Jinzhou Chen, Jingbo Chen, Yanlin Song, Xuying Liu. Intrinsic carbon nanotube liquid crystalline elastomer photoactuators for high-definition biomechanics. Materials Horizons 2022, 9 (3) , 1045-1056. https://doi.org/10.1039/D1MH01810H
  8. Jiayou Zhao, Limei Zhang, Jian Hu. Varied Alignment Methods and Versatile Actuations for Liquid Crystal Elastomers: A Review. Advanced Intelligent Systems 2022, 4 (3) https://doi.org/10.1002/aisy.202100065
  9. Xiaowei Xu, Xinyue Hao, Jing Hu, Weisheng Gao, Nanying Ning, Bing Yu, Liqun Zhang, Ming Tian. Recyclable silicone elastic light-triggered actuator with a reconfigurable Janus structure and self-healable performance. Polymer Chemistry 2022, 13 (6) , 829-837. https://doi.org/10.1039/D1PY01632F
  10. Jolanta Konieczkowska, Anna Kozanecka-Szmigiel, Karolina Bujak, Dariusz Szmigiel, Jan Grzegorz Małecki, Ewa Schab-Balcerzak. Photoresponsive behaviour of “T-type” azopolyimides. The unexpected high efficiency of diffraction gratings, modulations and stability of the SRG in azopoly(ether imide). Materials Science and Engineering: B 2021, 273 , 115387. https://doi.org/10.1016/j.mseb.2021.115387
  11. Mikołaj Rogóż, Jakub Haberko, Piotr Wasylczyk. Light-Driven Linear Inchworm Motor Based on Liquid Crystal Elastomer Actuators Fabricated with Rubbing Overwriting. Materials 2021, 14 (21) , 6688. https://doi.org/10.3390/ma14216688
  12. Chongyu Zhu, Yao Lu, Lixin Jiang, Yanlei Yu. Liquid Crystal Soft Actuators and Robots toward Mixed Reality. Advanced Functional Materials 2021, 31 (39) https://doi.org/10.1002/adfm.202009835
  13. Ziying Liang, Yingfeng Tu, Fei Peng. Polymeric Micro/Nanomotors and Their Biomedical Applications. Advanced Healthcare Materials 2021, 10 (18) https://doi.org/10.1002/adhm.202100720
  14. Adithya Ramgopal, Akhil Reddy Peeketi, Ratna Kumar Annabattula. Numerical analysis and design of a light-driven liquid crystal polymer-based motorless miniature cart. Soft Matter 2021, 17 (33) , 7714-7728. https://doi.org/10.1039/D1SM00411E
  15. Alissa Potekhina, Changhai Wang. Numerical simulation and experimental validation of bending and curling behaviors of liquid crystal elastomer beams under thermal actuation. Applied Physics Letters 2021, 118 (24) https://doi.org/10.1063/5.0053302
  16. Józef Szudy. 100 lat optyki na Uniwersytecie Warszawskim (1921–2021). 2021https://doi.org/10.31338/uw.9788323550211
  17. Yubing Guo, Hamed Shahsavan, Metin Sitti. 3D Microstructures of Liquid Crystal Networks with Programmed Voxelated Director Fields. Advanced Materials 2020, 32 (38) https://doi.org/10.1002/adma.202002753
  18. Przemysław Grabowski, Jakub Haberko, Piotr Wasylczyk. Photo-Mechanical Response Dynamics of Liquid Crystal Elastomer Linear Actuators. Materials 2020, 13 (13) , 2933. https://doi.org/10.3390/ma13132933
  • Abstract

    Figure 1

    Figure 1. (a) Dynamic deformation induced in the stator (orange) interacts via friction forces with the rotor ring (blue). (b) Traveling deformation of the liquid crystalline polymer ring (orange), induced by a spatially modulated laser beam, interacts with the stationary substrate (blue), and thus, the ring rotates around the vertical axis. (c) Photothermally induced deformation traveling along the rotor circumference (time t1 < t2 < t3 < t4, VTW—velocity of the traveling wave) results in each point on the surface following a regular orbit (grey dashed line). When the rotor comes in contact with a stationary substrate, the static friction force FSF acts on the rotor and sets it in motion. The white scale bar is 2 mm long. Panel (a) is adapted from. (32)

    Figure 2

    Figure 2. (a) Cross-linked polymer chains (yellow) arranged in one direction in an LC polymer network stripe deform locally because of increased temperature. With efficient light-absorbing dye, the heating can be induced by light absorption from a laser beam. (b) LC monomer, cross-linker, dye (Disperse Red 1) and photoinitiator used in the LCN. The coloring is consistent with panel (a). (c,d) Orientation of the molecular director n at the top and bottom surfaces of the cells used for preparing the LCN films: azimuthal (A) and radial (R). Two types of LCN films were prepared: A–A and A–R. Blue rings present how the micromotor rotor was cut from the film. (e,f) A–A and A–R cells filled with the LCN mixture, observed with a polarizing optical microscope (the arrows indicate the polarizer and analyzer orientation). The white scale bars in the photos are 10 mm long.

    Figure 3

    Figure 3. (a) Schematic of the experimental setup. The laser beam is reflected from a rotating mirror and sweeps around the LCN rotor ring. (b) Static LCN ring deformation due to the photomechanical response: yellow and red (computer-added colors) areas are images of the ring without and with the laser on, respectively. The white scale bar in the photo is 1 mm long. (c) LCN micromotor speed varies with the increasing P/f ratio, where P is the laser power and f is the mirror rotation frequency. Rotor with A–R orientation. (d) Same as (c) for the rotor with A–A orientation. (e) Snapshots of the numerical simulation of the traveling LCN ring deformations for the A–R orientation. (f) Same as (e) for the A–A orientation.

    Figure 4

    Figure 4. Measured trajectory of one point at the LCN ring edge for two film orientations: A–A (a,c) and A–R (b,d). The white scale bars are 1 mm long. (a,b) Measured (tracked) position of the point at the rotor circumference. (c,d) x and y coordinates of the points in (a,b) vs time.

  • References

    ARTICLE SECTIONS
    Jump To

    This article references 41 other publications.

    1. 1
      Yamada, M.; Kondo, M.; Mamiya, J.-i.; Yu, Y.; Kinoshita, M.; Barrett, C. J.; Ikeda, T. Photomobile Polymer Materials: Towards Light-Driven Plastic Motors. Angew. Chem., Int. Ed. 2008, 47, 49864988,  DOI: 10.1002/anie.200800760
    2. 2
      Wang, H.; Pumera, M. Fabrication of Micro/Nanoscale Motors. Chem. Rev. 2015, 115, 87048735,  DOI: 10.1021/acs.chemrev.5b00047
    3. 3
      Xu, L.; Mou, F.; Gong, H.; Luo, M.; Guan, J. Light-Driven Micro/Nanomotors: From Fundamentals to Applications. Chem. Soc. Rev. 2017, 46, 69056926,  DOI: 10.1039/c7cs00516d
    4. 4
      Chen, H.; Zhao, Q.; Du, X. Light-Powered Micro/Nanomotors. Micromachines 2018, 9, 41,  DOI: 10.3390/mi9020041
    5. 5
      Degennes, P. G. One Type of Nematic Polymers. C. R. Seances Acad. Sci., Ser. B 1975, 281, 101103
    6. 6
      Sawa, Y.; Urayama, K.; Takigawa, T.; DeSimone, A.; Teresi, L. Thermally Driven Giant Bending of Liquid Crystal Elastomer Films with Hybrid Alignment. Macromolecules 2010, 43, 43624369,  DOI: 10.1021/ma1003979
    7. 7
      Yu, Y.; Nakano, M.; Ikeda, T. Directed Bending of a Polymer Film by Light - Miniaturizing a Simple Photomechanical System Could Expand its Range of Applications. Nature 2003, 425, 145,  DOI: 10.1038/425145a
    8. 8
      Braun, L.; Linder, T.; Hessberger, T.; Zentel, R. Influence of a Crosslinker Containing an Azo Group on the Actuation Properties of a Photoactuating LCE System. Polymers 2016, 8, 435,  DOI: 10.3390/polym8120435
    9. 9
      Pevnyi, M.; Moreira-Fontana, M.; Richards, G.; Zheng, X.; Palffy-Muhoray, P. Studies of Photo-Thermal Deformations of Liquid Crystal Elastomers Under Local Illumination. Mol. Cryst. Liq. Cryst. 2017, 647, 228234,  DOI: 10.1080/15421406.2017.1289599
    10. 10
      Yang, H.; Buguin, A.; Taulemesse, J.-M.; Kaneko, K.; Méry, S.; Bergeret, A.; Keller, P. Micron-Sized Main-Chain Liquid Crystalline Elastomer Actuators with Ultralarge Amplitude Contractions. J. Am. Chem. Soc. 2009, 131, 1500015004,  DOI: 10.1021/ja905363f
    11. 11
      Urayama, K.; Honda, S.; Takigawa, T. Electrooptical Effects with Anisotropic Deformation in Nematic Gels. Macromolecules 2005, 38, 35743576,  DOI: 10.1021/ma0503054
    12. 12
      Spillmann, C. M.; Ratna, B. R.; Naciri, J. Anisotropic Actuation in Electroclinic Liquid Crystal Elastomers. Appl. Phys. Lett. 2007, 90, 021911,  DOI: 10.1063/1.2420780
    13. 13
      Urayama, K. Selected Issues in Liquid Crystal Elastomers and Gels. Macromolecules 2007, 40, 22772288,  DOI: 10.1021/ma0623688
    14. 14
      Kumar, K.; Knie, C.; Bleger, D.; Peletier, M. A.; Friedrich, H.; Hecht, S.; Broer, D. J.; Debije, M. G.; Schenning, A. A Chaotic Self-Oscillating Sunlight-Driven Polymer Actuator. Nat. Commun. 2016, 7, 11975,  DOI: 10.1038/ncomms11975
    15. 15
      Cheng, Z.; Wang, T.; Li, X.; Zhang, Y.; Yu, H. NIR-Vis-UV Light-Responsive Actuator Films of Polymer-Dispersed Liquid Crystal/Graphene Oxide Nanocomposites. ACS Appl. Mater. Interfaces 2015, 7, 2749427501,  DOI: 10.1021/acsami.5b09676
    16. 16
      Tabiryan, N.; Serak, S.; Dai, X.-M.; Bunning, T. Polymer Film with Optically Controlled Form and Actuation. Opt. Express 2005, 13, 74427448,  DOI: 10.1364/opex.13.007442
    17. 17
      Martella, D.; Nocentini, S.; Micheletti, F.; Wiersma, D. S.; Parmeggiani, C. Polarization-Dependent Deformation in Light Responsive Polymers Doped by Dichroic Dyes. Soft Matter 2019, 15, 13121318,  DOI: 10.1039/c8sm01954a
    18. 18
      Gelebart, A. H.; Jan Mulder, D.; Varga, M.; Konya, A.; Vantomme, G.; Meijer, E. W.; Selinger, R. L. B.; Broer, D. J. Making Waves in a Photoactive Polymer Film. Nature 2017, 546, 632636,  DOI: 10.1038/nature22987
    19. 19
      Liu, X.; Kim, S.-K.; Wang, X. Thermomechanical Liquid Crystalline Elastomer Capillaries with Biomimetic Peristaltic Crawling Function. J. Mater. Chem. B 2016, 4, 72937302,  DOI: 10.1039/c6tb02372j
    20. 20
      Ma, S.; Li, X.; Huang, S.; Hu, J.; Yu, H. A Light-Activated Polymer Composite Enables On-Demand Photocontrolled Motion: Transportation at the Liquid/Air Interface. Angew. Chem., Int. Ed. 2019, 58, 26552659,  DOI: 10.1002/anie.201811808
    21. 21
      Cheng, Z.; Ma, S.; Zhang, Y.; Huang, S.; Chen, Y.; Yu, H. Photomechanical Motion of Liquid-Crystalline Fibers Bending Away from a Light Source. Macromolecules 2017, 50, 83178324,  DOI: 10.1021/acs.macromol.7b01741
    22. 22
      Bisoyi, H. K.; Li, Q. Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications. Chem. Rev. 2016, 116, 1508915166,  DOI: 10.1021/acs.chemrev.6b00415
    23. 23
      Zeng, H.; Wasylczyk, P.; Wiersma, D. S.; Priimagi, A. Light Robots: Bridging the Gap between Microrobotics and Photomechanics in Soft Materials. Adv. Mater. 2018, 30, 1703554,  DOI: 10.1002/adma.201703554
    24. 24
      Ge, F.; Zhao, Y. Microstructured Actuation of Liquid Crystal Polymer Networks. Adv. Funct. Mater. 2020, 30, 1901890,  DOI: 10.1002/adfm.201901890
    25. 25
      Geng, Y.; Almeida, P. L.; Fernandes, S. N.; Cheng, C.; Palffy-Muhoray, P.; Godinho, M. H. A Cellulose Liquid Crystal Motor: A Steam Engine of the Second Kind. Sci. Rep. 2013, 3, 1028,  DOI: 10.1038/srep01028
    26. 26
      Ahn, C.; Li, K.; Cai, S. Light or Thermally Powered Autonomous Rolling of an Elastomer Rod. ACS Appl. Mater. Interfaces 2018, 10, 2568925696,  DOI: 10.1021/acsami.8b07563
    27. 27
      Lu, X.; Guo, S.; Tong, X.; Xia, H.; Zhao, Y. Tunable Photocontrolled Motions Using Stored Strain Energy in Malleable Azobenzene Liquid Crystalline Polymer Actuators. Adv. Mater. 2017, 29, 1606467,  DOI: 10.1002/adma.201606467
    28. 28
      Morita, T. Miniature Piezoelectric Motors. Sens. Actuators, A 2003, 103, 291300,  DOI: 10.1016/s0924-4247(02)00405-3
    29. 29
      Oh, J.-H.; Jung, H.-E.; Lee, J.-s.; Lim, K.-J.; Kim, H.-H.; Ryu, B.-H.; Park, D.-H. Design and Performances of High Torque Ultrasonic Motor for Application of Automobile. J. Electroceram. 2009, 22, 150155,  DOI: 10.1007/s10832-008-9434-1
    30. 30
      Spanner, K.; Koc, B. Piezoelectric Motors, an Overview. Actuators 2016, 5, 6,  DOI: 10.3390/act5010006
    31. 31
      Rogóż, M.; Zeng, H.; Xuan, C.; Wiersma, D. S.; Wasylczyk, P. Light-Driven Soft Robot Mimics Caterpillar Locomotion in Natural Scale. Adv. Opt. Mater. 2016, 4, 16891694,  DOI: 10.1002/adom.201600503
    32. 32
      Bar-Cohen, Y.; Bao, X. Q.; Grandia, W. Rotary Ultrasonic Motors Actuated by Traveling Flexural Waves. Proc. SPIE 1999, 3668, 698704
    33. 33
      de Haan, L. T.; Sanchez-Somolinos, C.; Bastiaansen, C. M. W.; Schenning, A.; Broer, D. J. Engineering of Complex Order and the Macroscopic Deformation of Liquid Crystal Polymer Networks. Angew. Chem., Int. Ed. 2012, 51, 1246912472,  DOI: 10.1002/anie.201205964
    34. 34
      Rogóż, M.; Dradrach, K.; Xuan, C.; Wasylczyk, P. A Millimeter-Scale Snail Robot Based on a Light-Powered Liquid Crystal Elastomer Continuous Actuator. Macromol. Rapid Commun. 2019, 40, 1900279,  DOI: 10.1002/marc.201900279
    35. 35
      Küpfer, J.; Finkelmann, H. Nematic Liquid Single-Crystal Elastomers. Makromol. Chem., Rapid Commun. 1991, 12, 717726,  DOI: 10.1002/marc.1991.030121211
    36. 36
      Finkelmann, H.; Nishikawa, E.; Pereira, G. G.; Warner, M. A New Opto-Mechanical Effect in Solids. Phys. Rev. Lett. 2001, 87, 015501,  DOI: 10.1103/physrevlett.87.015501
    37. 37
      Li, M.-H.; Keller, P. Artificial Muscles Based on Liquid Crystal Elastomers. Philos. Trans. R. Soc., A 2006, 364, 27632777,  DOI: 10.1098/rsta.2006.1853
    38. 38
      McConney, M. E.; Martinez, A.; Tondiglia, V. P.; Lee, K. M.; Langley, D.; Smalyukh, I. I.; White, T. J. Topography from Topology: Photoinduced Surface Features Generated in Liquid Crystal Polymer Networks. Adv. Mater. 2013, 25, 58805885,  DOI: 10.1002/adma.201301891
    39. 39
      Ahn, S.-k.; Ware, T. H.; Lee, K. M.; Tondiglia, V. P.; White, T. J. Photoinduced Topographical Feature Development in Blueprinted Azobenzene-Functionalized Liquid Crystalline Elastomers. Adv. Funct. Mater. 2016, 26, 58195826,  DOI: 10.1002/adfm.201601090
    40. 40
      Zeng, H.; Martella, D.; Wasylczyk, P.; Cerretti, G.; Lavocat, J.-C. G.; Ho, C.-H.; Parmeggiani, C.; Wiersma, D. S. High-Resolution 3D Direct Laser Writing for Liquid Crystalline Elastomer Microstructures. Adv. Mater. 2014, 26, 23192322,  DOI: 10.1002/adma.201305008
    41. 41
      Zeng, H.; Wasylczyk, P.; Parmeggiani, C.; Martella, D.; Burresi, M.; Wiersma, D. S. Light-Fueled Microscopic Walkers. Adv. Mater. 2015, 27, 38833887,  DOI: 10.1002/adma.201501446
  • Supporting Information

    Supporting Information

    ARTICLE SECTIONS
    Jump To

    The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.9b20309.

    • Chemical structure and characterization of the PI, DSC, and DMTA characterization of the LCN films (PDF)

    • Rotating micro-motor with A–R orientation (MP4)

    • Rotating micro-motor with A–A orientation (MP4)

    • Numerical simulation results for the photomechanical response of an LCN rotor ring with A–R orientation (MP4)

    • Numerical simulation results for the photomechanical response of an LCN rotor ring with A–A orientation (MP4)

    • Temperature distribution in the rotating micro-motor (MP4)

    • Ring micro-motor turning a tube on the axis (MP4)


    Terms & Conditions

    Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

You’ve supercharged your research process with ACS and Mendeley!

STEP 1:
Click to create an ACS ID

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

MENDELEY PAIRING EXPIRED
Your Mendeley pairing has expired. Please reconnect