Optical actuator

Abstract

To provide an optical actuator for creating mechanical movement for a direct operation.SOLUTION: An actuator powered by photonic energy comprises a main body including a material which deforms from a first undeformed state when exposed to electromagnetic radiation to a second deformed state and begins to return to the first undeformed state when the electromagnetic radiation is removed. The actuator further comprises a stationary element affixed to the main body, and a moving element engaging the stationary element at least when the main body is in the second deformed state. Deformation of a deformable material in response to applied electromagnetic radiation is transmitted to the moving element by friction between the stationary element and the moving element for causing motion of the moving element, via the stationary element.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] [Government Rights] This invention was made with Government support under NCI Grant #ROI CA166379 awarded by the National Institutes of Health. The Government has certain rights in this invention.

[0002] Optical actuators are described, and more particularly, optical actuators that create mechanical movement for direct work. [Background technology]

[0003] Actuator designs vary depending on the intended use. For example, MRI machines have strong magnetic fields, and MRI compatible robotics is a growing field. Conventional non-ferrous piezoelectric motors can be made MRI compatible, but are not MRI safe. The non-ferrous materials of conventional piezoelectric actuators affect the homogeneity of the MRI's BO field (external static magnetic field), causing distortions and reducing image quality. Pneumatic and hydraulic actuators can be made without metal components, but this can reduce precision and increase size. Summary of the Invention

[0004] In a vacuum environment, a conventional motor can be remotely operated and powered by an on-board battery. However, the operating time is limited to the battery life. Although a special seal can be made where the motor cable crosses the vacuum seal, this adds complexity to the design of the vacuum chamber and introduces a source of failure.

[0005] In explosive environments, such as the fuel tanks of an aircraft, the motors should be shielded, i.e. operated at low voltages which reduces the risk of sparking. For example, piezoelectric motors do not arc.

[0006] For the reasons discussed above, there is a need for new actuators that do not require electronics or metal components at or near the actuation point. The actuators should be MRI safe and usable in vacuum and explosive environments. Ideally, the actuators would be injection moldable or 3D printable.

[0007] For a more complete understanding of the optical actuator, reference should now be made to the embodiments illustrated in the accompanying drawings and described below. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an embodiment of an optically actuated photostrictive actuator. [Diagram 2] FIG. 13 is a perspective view of another embodiment of a photostrictive actuator. [Diagram 3] FIG. 3 is a schematic side view of a light source for use with the photostrictive actuator shown in FIGS. 1 and 2. [Figure 4] 1 is a perspective view of an embodiment of a piezoelectric actuator. [Diagram 5] FIG. 3 is a schematic diagram of multiple light sources for use with the photostrictive actuator shown in FIGS. 1 and 2. [Figure 6] FIG. 3 is a schematic side view of multiple movable light sources for use with the photostrictive actuator shown in FIGS. 1 and 2. [Figure 7] FIG. 1 illustrates an embodiment of a photostric actuator for providing vibration or sound. [Figure 8] FIG. 2 is a schematic diagram of another embodiment of a photostrictive actuator. [Figure 9] 9 is a graph showing two patterns of pulsed light output provided to a light generator of the actuator shown in FIG. 8. [Figure 10] FIG. 1 shows an azobenzene LCP that deforms when exposed to ultraviolet light with a wavelength of 450 nm and returns to a non-deformed state when exposed to ultraviolet light with a wavelength of 365 nm. [Figure 11] FIG. 2 is a schematic diagram of another embodiment of a photostrictive actuator. [Figure 12] 12 is a graph showing two patterns of pulsed light output provided to a light generator of the actuator shown in FIG. 11. [Figure 13] 1 is a schematic diagram of an embodiment of a rotary motor. [Figure 14] FIG. 1 is a schematic diagram of an embodiment of a two-sided drive linear motor. [Figure 15a] FIG. 1 is a schematic diagram of an embodiment of a multi-directional stack motor in a relaxed state. [Figure 15b] FIG. 1 is a schematic diagram of an embodiment of a multi-directional stack motor in an activated state. [Figure 16] FIG. 15B is a schematic diagram of the light output on the illumination surface of the multi-directional stack motor shown in FIGS. 15a and 15b. [Figure 17] 15b is a graph showing four patterns of pulsed light output provided to the multi-directional stack motor shown in FIG. 15a and FIG. 15b. [Figure 18] FIG. 1 is a schematic diagram of an embodiment of a device for use in an underwater environment. [Figure 19] 1 is a schematic diagram of an embodiment of an apparatus for use in a vacuum environment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Certain terms are used herein for convenience only and should not be construed as limiting. For example, terms such as "upper", "lower", "left", "right", "horizontal", "vertical", "upward", "downward", "top", "bottom", etc. are merely descriptive of the configurations shown in the figures. In fact, components may be oriented in any direction, and therefore such terms should be understood to encompass variations unless otherwise specified. The terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of the core and designated portions thereof. The terms include those specifically mentioned above, derivatives thereof, and similar foreign words.

[0010] Photostrictive actuators, i.e., light-activated mechanical actuators, include materials that deform when exposed to light or other electromagnetic radiation and return substantially, but not completely, to their original undeformed state when the light or other radiation is removed under hysteresis effects. The deformable material may be a layer of lanthanum-doped lead zirconate titanate (PLZT). In other embodiments, the deformable material may be another material that has a photoactive strain, including, but not limited to, lead magnesium niobate-lead titanate (PMN-PT), BiFeO3, and some liquid crystal polymers (LCPs) that contain azobenzene. A single ultraviolet (UV) light source deforms PLZT, PMN-PT, and BiFeO3. The desired deformation is produced by controlling the duration of the light supply that the material is exposed to. Various types of light sources can be used, including various spectra, including central wavelengths and associated full width at half maximum (FWHM). The light source, or portions thereof, used to control the actuator may be pulsed on and off, or may be variably controlled in intensity.

[0011] In one form, (Pb0.97La0.03)(Zr0.52Ti0.48)1-0.03 / 403 [PLZT(3 / 52 / 48)] doped with 0.5% W03 has a wavelength of 366 nm and a power density of 10 mW / cm 2Under a UV light source of 450 nm, the phase-change pulsed light system can be applied to any material. The response time of PLZT (3 / 52 / 48), for example, is typically slow, a few seconds up to a minute. As a variant, PMN-PT-32% has a relatively large piezoelectric constant and a relatively fast response time, about 1 second. Although BiFeO3 works with a lower photostrictive efficiency than optimized PLZT ceramics, single crystals of BiFeO3 are more suitable for some applications due to their faster response time, about 100 μs or less. Azobenzene LCP deforms when exposed to UV light with a wavelength of 450 nm and returns to the undeformed state when exposed to UV light with a wavelength of 365 nm (FIG. 10). Phase-change pulsed light systems can be applied to any material. Different materials have different time scales for contraction and expansion, and appropriate dynamic parameters can be adjusted by material selection and preparation and light source configuration and control. Different materials with different temporal or spectral responses may be combined into a single actuator to control the overall motion, and in some embodiments the motion of different parts of the actuator may be fully or partially decoupled.

[0012] The light from the light source can be controlled and the light pattern can be designed and customized for application to the photostrictive material. In one form, the light guide can be comprised of one or more fiber optic cables and can output the desired pattern. In one embodiment, the light output is converted to a pulsed light output having a predetermined pattern via a pulsed light generator. A laser generates a light output in a spectrum between 300 nm and 10,000 nm. Suitable lasers can be selected from lasers including, but not limited to, Ar-ion lasers, Nd:YAG lasers, Ti:sapphire lasers, tunable solid-state and dye lasers, semiconductor lasers, and carbon dioxide lasers. As mentioned above, a control system can be applied to generate a light output of variable intensity. The desired light output can be emitted by an optical system, which includes a device that generates a light output in the visible or infrared spectrum and other guides through lenses or other couplers.

[0013] Referring to the drawings, an embodiment of a photostric actuator, i.e., a light-activated mechanical actuator, is shown in Figure 1 and generally designated by the numeral 100. The actuator includes a material 101 that deforms when exposed to light or other electromagnetic radiation and substantially returns to a first, undeformed state, partially under a hysteresis effect, when such light or the like is removed. In one embodiment, material 101 may be a separate component bonded to other layers of actuator 100 or may be directly attached to other materials.

[0014] The embodiment of the actuator as seen in Figure 1 further comprises a stator 102. The light-actuated material 101 is coupled to the stator 102 which has the function of transmitting the deformation of the light-actuated material 101.

[0015] The deformation of the material 101 is caused by one or more light sources 103, 104, including multiple light sources that illuminate the material 101. The light sources 103, 104 may be fully integrated into the fixture, such as, but not limited to, multiple LEDs or lasers. The light sources may be located within the motor enclosure together with the actuator 100. Alternatively, multiple light generators may be remote from the actuator 100 or actuation site and optically coupled to the light sources 103, 104, for example via optical fibers or other light guides. In this form, one or more lenses may be located within the body of the motor enclosure.

[0016] Stator 102 is frictionally coupled to moving element 105. Deformations are transmitted by stator 102 to moving element 105, which converts the deformations transmitted by stator 102 into motion of moving element 105. In one embodiment, stator 102 has a predetermined periodic pattern of deformations.

[0017] In one embodiment, the actuator 100 is a rotary motor. A light actuating material 101 bonded to a stator 102 deforms when exposed to light sources 103, 104, causing rotation of a moving element 105. The moving element 105 thus acts as a rotor. In this rotary motor embodiment, a rotating shaft 106 or some form of attachment such as a mounting hole pattern is mechanically coupled to the motor, and the operation of the rotary motor is used by an external device.

[0018] In one application, the material 101 and the stator 102 are fixed in space and the rotor 105 moves relative to the material 101 and the stator 102. This configuration has the advantage of allowing the light sources 103, 104 to also remain fixed. However, it should be understood that the material 101 and the stator 102 may move relative to the rotor 105 which remains as a fixed element.

[0019] Another embodiment of a photostric actuator is shown in FIG. 2. This embodiment of the actuator includes a material 201 that deforms when exposed to light or other electromagnetic radiation and returns substantially to a non-deformed state when the light or the like is removed. The material 201 is disposed on a stator 202. The stator 202 is used to generate translational motion along one or more degrees of freedom that correspond to an adjacent flat or spherical moving body 205. The moving body 205 may be arranged to be pressed against gravity via a spring or mass 207 against the stator 202. The moving body 205 may be attached via a protrusion or mounting hole pattern 206 or may be used to directly push or pull another object. It should be understood that this configuration does not exclude the situation where the moving body 205 may be part of another object to be actuated. This configuration also does not exclude configurations where the moving body 205 may be rotated in addition to or instead of being translated.

[0020] Referring to FIG. 3, a light source 301 is used to generate light or other electromagnetic radiation. The light source 301 may be coupled to an optical demultiplexer 303. The optical demultiplexer may include a beam splitter and an acoustic shutter that directs the generated light or other electromagnetic radiation at a predetermined time into a fiber 304 or other guide that extends to a material 101, 201 that deforms when exposed to light or the like. However, it should be understood that the output from the acoustic demultiplexer 303 may be directly coupled to a target portion. In another embodiment shown in FIG. 5, multiple light sources 501 are each coupled to a lens 503 or another coupler via a fiber or other guide 504.

[0021] A regular piezoelectric actuator 400 (FIG. 4) or its equivalent can be converted into an optical actuator by the addition of an optoelectronic converter 403. The optoelectronic converter 403 may be attached directly to the piezoelectric material 401 or another material with electrically dependent strain characteristics.

[0022] 6, optical end 602 may be spaced apart from or bonded to material 603, which deforms when exposed to light or other electromagnetic radiation and returns to a substantially undeformed state when such light or the like is removed. It should be understood that optical end 602 may be movable relative to material 603.

[0023] The embodiment of the actuator shown in FIG. 7 may be used to create various pressures in a medium where sound needs to be produced. This embodiment of the actuator includes a material 701 that deforms when exposed to light or other electromagnetic radiation. This material is attached to a layer 702 that transmits, couples or amplifies the vibrations onto an element 703 that is coupled to or displaces the medium. The element 703 resides within the medium and may be cone-shaped, flat, circular or other form configured to displace the medium. However, it should be understood that the actuator may also create pressures in the medium without being completely, i.e., not present at all, within the medium.

[0024] Another embodiment of an actuator is shown in FIG. 8 and generally designated by the numeral 800. In this embodiment, the actuator 800 includes a light-activated material 801, which may be a separate component bonded to other layers or may be directly attached to another material acting as a stator. A rotor 802 is coupled to a surface of the light-activated material 801 with high pressure in a direction toward the stator as indicated by arrow 809 in FIG. 8. A light source 805 generates a light output that passes through a light guide 808. In one embodiment, the light guide 808 is comprised of one or more optical fibers. In one form, the light guide 808 is a multimode fiber optic cable. The light output is transmitted through the fiber optic cable 808 to one form of an optical system 803, 804, which directs the light output onto an illumination surface of the light-activated material 801 to activate illumination areas. In one embodiment, the light output is converted to a pulsed light output via pulsed light generators 806, 807. As shown in FIG. 9, a plurality of first pulsed light generators 806 provide a pattern 901, and a plurality of second pulsed light generators 807 provide another pattern 902. The shape of the activated area changes with these patterns, generating directional moving waves indicated by arrows 810. The moving waves engage the surface of the rotor 802 at each of the individual wave peaks of the elliptical orbit 811, where the rotor 802 is frictionally coupled to the light actuating material 801 for output to generate motion. The rotor 802 moving direction 812 indicated by arrows 812 is opposite to the direction 810 along which the moving waves travel.

[0025] In another embodiment shown in FIG. 11, the light-actuated material 1101 comprises azobenzene LCP. The light-actuated material 1101 may be a separate component bonded to other layers or may be directly attached to another material acting as a stator. A rotor 1102 is coupled to the surface of the light-actuated material 1101 at high pressure in a direction toward the stator indicated by arrow 1110 in FIG. 10. The light sources 905, 906 generate various light outputs that pass through a light guide 1109. In one embodiment, the light guide 1109 includes one or more optical fibers. In this form, ultraviolet light of 365 nm wavelength and 450 nm wavelength, respectively, enters the multimode fiber optic cable 1109. In one embodiment, each light output is converted to a pulsed light output via a pulsed light generator 1107, 1108. The pulsed light follows the pattern shown in FIG. 12. In one form, one optical output 1107 has two pulse patterns 1001, 1003 and the other optical output 1108 has another two pulse patterns 1202, 1204.

[0026] The optical power is transmitted via fiber optic cables to two optical system configurations 1103, 1104, each designed to direct the optical power onto an illumination surface of the light-actuating material 1101, activating the illuminated area. The shape of the activated area deforms, generating a directional traveling wave indicated by arrow 1112. The traveling wave engages the surface of the rotor 1102 at each of the individual wave peaks of the elliptical orbit, where the rotor is frictionally coupled to the light-actuating material 1101 for output to generate motion. The rotor 1102 movement direction indicated by arrow 1113 is opposite the direction 1112 in which the traveling wave travels. The rotor 1102 rotates in the direction indicated by arrow 1113, which is opposite the direction 1112 of the traveling wave.

[0027] An embodiment of a rotary motor is shown in FIG. 13 and generally indicated by the numeral 1300. The rotary motor 1300 includes a photostrictive material 1301 that functions as a stator. A rotor 1302 is mated with the surface of the stator under high pressure in the direction indicated by the arrow 1306. In one form, the light output is transmitted via an optical cable 1305 to one form of an optical system 1303, 1304 that is designed to direct the light output onto the illumination surface of the photostrictive material 1301. As described above, the light provided follows the activated pattern. The shape of the activated area of ​​the photostrictive material is deformed, generating a directional moving wave indicated by the arrow 1308. The rotor 1302 engages the stator only at each of the individual wave peaks of the elliptical orbit, where the rotor is frictionally engaged to the photostrictive material 1301 for the output to generate motion. The direction of movement 1309 of the rotor 1302 is opposite to the direction of travel of the traveling wave indicated by arrow 1308. The rotor 1302 rotates in the direction 1309 opposite to the direction 1308 of the traveling wave.

[0028] Referring to FIG. 14, an embodiment of a two-sided drive linear motor is shown and generally designated by the numeral 1400. The linear motor 1400 includes a pair of layers of photostrictive material 1401 acting as a stator. A slider 1402 is sandwiched between the top and bottom layers of the stator. High voltage is applied across these layers in the direction indicated by the arrow 1405. In one form, the light output is transmitted via an optical cable 1404 to an optical array system 1403 that is designed to direct the light output onto the illumination surface of the photostrictive material 1401. The light is provided in a pattern as described above. The T-shape of the activated area of ​​the photostrictive material 1401 deforms, generating a traveling wave 1407. The slider 1402 contacts the stator only at each of the peaks of the corrugations on both the top and bottom surfaces. The multiple peaks of the waveform enforce a trajectory, e.g., an elliptical trajectory, movement 1407 of the surface particles. The direction of movement of this trajectory 1406 of the surface particles is opposite to the direction of the moving wave 1407. The slider moves in a direction 1408 opposite to the moving wave 1407.

[0029] 15a and 15b, a multi-directional stack motor is shown and generally designated by the numeral 1500. In one embodiment, the stack motor 1500 includes two forms of polymeric photostric material stacked on top of each other in a desired array configuration. In one arrangement, a 2x2x5 array of two forms of material is stacked. An output element 1502 is placed in the center of the top surface of the array 1501. A light source 1503 generates a light output that passes through the light guide. In one embodiment, the light output is converted to a pulsed light output via a pulsed light generator 1504 according to the exemplary phase shift patterns 1701-1704 shown in FIG. 17. One light source follows one pulse pattern 1701. Two light sources follow a second pulse pattern 1702. Three light sources follow a third pulse pattern 1703. Four light sources follow a fourth pulse pattern 1704. The light output is transmitted into a multimode fiber optic cable 1505 and reflected and spread on the illuminated surface of the material (FIG. 16). Another embodiment may be a fiber sensor connector or a fiber end coupling and deployment method. The output light is transmitted from the fiber optic cable 1603 to one form of the optical system 1602. In one embodiment, a two-layer array of 45° reflective micromirrors 1607, 1608 is placed between two layers of a two-form polymeric photostric material 1601. When the light output 1606 is illuminating, the light is reflected by the micromirror array and illuminates the surface of the material 1601. In one form, the light output is passed through a front mirror and reaches an end mirror. The power loss and reflection ratio of the light must be considered. Under the arrangement shown in FIG. 17, the entire stacked array is twisted around and the output elements rotate on a surface parallel to the ground. In another embodiment, the pattern may have a different phase shift setting, for example overlapping 30° phase shifts, causing the output elements to rotate on a surface parallel to the ground and in a smaller circle. An alternative switchable actuation pulse pattern may be, for example, output pulses 1 and 3 only, no outputs 2 and 4, and the output elements to rotate on a surface perpendicular to the ground.

[0030] FIG. 18 shows an embodiment of the device under water environment application, the device is generally designated by the numeral 1800. In one embodiment, the device 1800 includes a motor 1801 located in a water tank 1803 and below the surface of the water 1804. In one form, a pulsed light output is transmitted to an optical system 1805 via an optical cable 1806, which is designed to direct the light output. The light output 1807 illuminates the water at 1808, which reflects the light output, but mainly refracts the light output into the water at an angle 1809, thereby illuminating the surface of the photostrictive material 1802 and exciting and deforming the photostrictive material 1802. The power loss of the light output due to reflection, refraction, and passage through the water must be carefully considered. Also, the position of the actuator 1800 and the light output must be aligned to deliver maximum light power density. It should be understood that different liquids having different refractive indices may be used as well as multiple layers of liquids.

[0031] FIG. 19 shows an embodiment of an apparatus for use within a vacuum chamber environment, the apparatus generally designated 1900. In one embodiment, the apparatus 1900 has an actuator 1901 located inside a vacuum chamber 1903. In one form, the vacuum chamber 1903 has a top surface, which includes a glass window 1904 or other transparent material with a sufficient extinction coefficient. An external pump 1905 maintains a vacuum condition 1911 within the vacuum chamber 1903. In use, pulsed optical power is transmitted via optical cable 1907 to an optical system 1906, which is designed to direct the optical power. The optical power 1908 illuminates the glass at 1909. The optical power is reflected, but primarily transmitted 1910 through the glass, thereby illuminating the surface of the photostrictive material 1902 and exciting and deforming the photostrictive material 1902. In one embodiment, the power loss of the optical output due to the optical absorption coefficient of the transparent material must be considered. Also, the position of the actuator 1901 and the optical output must be aligned to deliver maximum optical power density. In another embodiment, a nested vacuum chamber configuration may be applied. In this configuration, the dual transparent material absorption must be considered. In another embodiment, a superconducting environment of ultra-low temperature and ultra-high pressure may be applied in this configuration.

[0032] A photostrictive actuator as described herein has many advantages, including providing a type of optical motor that is compatible in unique environments, such as MRI machines, vacuum environments, explosive environments, etc. A photostrictive actuator can safely operate in the strong magnetic fields of MRI machines, magnetoencephalograms, or other NMR devices. Thus, a photostrictive actuator can achieve the highest interoperability rating of "MRI safe". In a vacuum environment, the drive signal to the photostrictive actuator can pass through a transparent window typically used in a vacuum chamber. Optical coupling allows the motor to be operated without wires that would break the vacuum seal. This may also be applied to underwater applications. A photostrictive actuator can operate without battery life limitations. A photostrictive actuator can operate in an explosive environment without any electronics, thereby eliminating the hazards associated with motor sparks.

[0033] Photostrictive actuators also work in other highly sensitive environments, for example for use in instruments where electronics must be removed from the photostrictive actuator to minimize the chance of interference. This would be applicable to use in chemical instruments in terrestrial laboratories as well as space applications. Furthermore, the optical "back end" of the motor can be a large and complex device. However, at the point of actuation, the optical back end may be coupled to a very low-cost piezoelectric crystal (essentially just a ceramic disk) and does not necessarily require physical contact (i.e., across the sterile boundary). This configuration is ideal for the actuation module of a sterile, single-use surgical kit. Microactuation techniques are possible by remotely locating the optical unit and placing a highly focused small optical fiber or light guide at the photostrictive actuator.

[0034] A resonant motor works as an underwater ultrasonic module if it is made into a vibrator or speaker and is made of non-corroding parts and has no wires that lose conductivity in ionic environments. In aerospace applications, optical coupling allows the motor to be operated without a wire-controlled setup, for example for use in rolling reaction wheels in the rotation angle of the Hubble Space Telescope. As in the above mentioned industries, other more direct solutions are possible without the need for tangential solutions such as batteries, shielding, etc.

[0035] Although the optical actuator has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, those skilled in the art should understand that the inventors do not intend to limit themselves to such embodiments, since various modifications, omissions, and additions may be made to the disclosed embodiments without substantially departing from the novel techniques and advantages of the present device, especially in light of the above-mentioned technology. Accordingly, the inventors intend to cover all and equivalent examples of such modifications, omissions, and additions as fall within the spirit and scope of the device, system, and method as defined by the claims. In the claims, the recitation of functional means refers to the structures described herein to perform the recited functions, structural equivalents, and not only equivalent structures. Thus, a pawl and a screw may not be structurally equivalent in that the pawl employs a cylindrical surface and the screw employs a helical surface to fasten wooden parts together, but in the context of fastening wooden parts, a pawl and a screw are equivalent structures.

Claims

1. 1. An actuator powered by photonic energy, comprising: a body including a material that transforms from a first undeformed state to a second deformed state when exposed to electromagnetic radiation and begins to return to the first undeformed state when the electromagnetic radiation is removed; a stationary element fixed to the body; a moving element that engages with the stationary element at least when the body is in the second deformation state; An actuator, wherein a deformation of the deformable material in response to applied electromagnetic radiation is transferred through the stationary element to the moving element by friction between the stationary element and the moving element to cause movement of the moving element.

2. The deformable materials include lead lanthanum-doped zirconate titanate (PLZT), lead magnesium niobate-lead titanate (PMN-PT), BiFeO 3 10. The actuator of claim 1, wherein the polymer is selected from the group consisting of azobenzene-containing liquid crystal polymers (LCPs).

3. The actuator of claim 1 , wherein the deformation comprises an elastic volumetric dimensional change of the deformable material of the body.

4. The actuator of claim 1 , further comprising an electromagnetic radiation source configured to generate an output, the electromagnetic radiation source positioned such that an optical output radiates toward a surface of the body.

5. The actuator of claim 4 , further comprising an optical guide for optically coupling the electromagnetic radiation source to the deformable material.

6. The actuator of claim 5 , wherein the optical guide is an optical fiber.

7. The actuator of claim 3 , wherein the source of electromagnetic radiation is a light source that generates an output.

8. The actuator of claim 7 , wherein the light source includes a light shaping optical device configured to focus a light output.

9. The actuator of claim 8 , wherein the light shaping optical device comprises an optical lens.

10. The actuator of claim 7 , wherein the light source is configured to generate a pulsed light output.

11. The actuator of claim 7 , wherein the light source comprises a laser source.

12. The actuator of claim 1 further comprising a spring or mass arranged to urge the moving element against the stationary element against gravity.

13. the motion is rotational and the moving element includes a rotor; The actuator of claim 1 , further comprising a rotatable output shaft coupled to the rotor.

14. The actuator of claim 1 , wherein the movement is a translation along one or more degrees of freedom.

15. The actuator of claim 1 , further comprising a mass operatively connected to move with said moving element.

16. The actuator of claim 1 , wherein the light source is coupled to an optical demultiplexer.

17. 17. The actuator of claim 16, wherein the optical demultiplexer is a beam splitter configured to distribute transmitted power from the electromagnetic radiation source for transmission to a plurality of surfaces of the body.

18. An optical actuator comprising: a piezoelectric actuator; and a photoelectric converter coupled to the piezoelectric actuator.

19. 1. An optical actuator comprising: a body including a material that transforms from a first undeformed state to a second deformed state when exposed to electromagnetic radiation and begins to return to the first undeformed state when the electromagnetic radiation is removed; a stationary element fixed to the body; a medium coupled to the stationary element; An optical actuator, wherein a deformation of the deformable material in response to applied electromagnetic radiation is transmitted to the medium via the stationary element to produce a displacement that creates a variable pressure in the medium.

20. The actuator of claim 13 , wherein the shape of the stationary element is selected from a cone shape, a flat shape, and a circular plane.

21. The actuator of claim 4 , wherein the output from the electromagnetic radiation source is controlled in a coordinated manner such that a periodic deformation occurs in the body to produce continuous movement of the moving element.

22. 22. The actuator of claim 21, wherein the generated continuous motion is a rotational motion.

23. 22. The actuator of claim 21, wherein the generated continuous motion is a linear motion.

24. The actuator of claim 10 , wherein the pulsed light output causes a reciprocating deformation of the body.

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