Fea Report Template

Shape-morphing alluring bendable machines are awful adorable for assorted applications in minimally invasive medicine, wearable devices, and bendable robotics. Despite contempo progress, accepted alluring programming approaches are inherently accompanying to consecutive artifact processes, preventing reprogrammability and high-throughput programming. Here, we address a high-throughput alluring programming action based on heating alluring bendable abstracts aloft the Curie temperature of the anchored ferromagnetic particles and reorienting their alluring domains by applying alluring fields during cooling. We authenticate discrete, three-dimensional, and reprogrammable magnetization with aerial spatial resolution (~38 μm). Appliance the reprogrammable magnetization capability, reconfigurable automatic behavior of an auxetic metamaterial structure, tunable locomotion of a surface-walking bendable robot, and adaptive acquisitive of a bendable gripper are shown. Our access added enables high-throughput alluring programming (up to 10 samples/min) via acquaintance transfer. Heat-assisted alluring programming action declared actuality establishes a affluent architecture amplitude and mass-manufacturing adequacy for development of multiscale and reprogrammable bendable machines.

Shape-morphing abstracts that can be actuated via alien stimuli, such as light, temperature, humidity, pH, and acoustic, electrical and alluring fields, authority abundant accent for approaching applications in minimally invasive anesthetic (1–3), implantable and wearable accessories (4, 5), bendable robotics (6–9), and micromachines (10–12). Magnetically acknowledging bendable abstracts with programmable appearance anamorphosis are decidedly adorable for fast, reversible, and circuitous morphing of bendable machines (5, 6, 10, 11, 13, 14). Magneto-active backdrop of these bendable machines axis from alluring micro/nanoparticles broadcast aural a bendable polymer matrix. Activated alluring fields accomplish torque on alluring bendable abstracts until the magnetization administration of all domains is accumbent with the acreage administration (15–17). Therefore, creating a spatial administration of magnetization admonition in a alluring bendable apparatus enables programmable appearance anamorphosis beneath alluring fields (6, 11, 13, 18–20).

Initial approaches for alluring programming of bendable machines await on template-assisted magnetization. A alluring bendable actual is askew into a agreed appearance beneath a saturating compatible alluring field, consistent in reorientation of the alluring domains in the acreage direction. When unfolded, the alluring bendable actual exhibits spatially capricious magnetization admonition (6, 18). Although template-assisted alluring programming allows accomplished encoding of anamorphosis instructions, creating detached three-dimensional (3D) magnetization profiles at baby scales is arduous due to intricate adjustment geometries and handling. Recently, added alluring programming approaches are alien for encoding detached 3D magnetization profiles in small-scale bendable machines based on concrete alignment and acclimation of the alluring particles during abating via lithographic or 3D press techniques (7, 13, 21). However, in these approaches, alluring programming is inherently accompanying to the artifact process, consistent in a abiding magnetization profile, which prevents reprogramming already bogus (7, 13, 21). Furthermore, consecutive magnetization and artifact processes associated with these approaches absolute high-throughput alluring programming.

Here, we acquaint a able action for encoding reprogrammable shape-morphing instructions into alluring bendable machines in a high-throughput fashion. Our access is enabled by heat-assisted alluring programming of bendable abstracts by heating aloft the Curie temperature of the ferromagnetic particles and reorienting their alluring domains with alien alluring fields during cooling (Fig. 1A). By heat-assisted magnetization, shape-changing instructions in 3D can be encoded discretely and reprogrammed on appeal with aerial resolution (~38 μm). Demography advantage of alluring reprogrammability, reconfigurable automatic behavior of an auxetic metamaterial structure, tunable locomotion patterns of a quadrupedal bendable robot, and adaptive acquisitive behavior of a bendable gripper are demonstrated. Heat-assisted alluring programming added enables high-throughput alluring programming via acquaintance alteration of broadcast magnetization profiles from a alluring adept (~10 samples/min appliance a distinct master). The alluring (re)programming access declared actuality is a able and able apparatus for the development of next-generation small-scale alluring bendable machines with aberrant shape-morphing capabilities.

(A) A alluring bendable elastomer, composed of alluring CrO2 particles anchored in PDMS, is locally acrimonious aloft the Curie temperature of the particles via a laser. Aloft the Curie temperature, the particles lose their abiding magnetization, and their magnetization administration is reoriented by applying an alien alluring acreage during cooling. R.T., allowance temperature. (B) The alluring bendable elastomer is acrimonious aloft the Curie temperature of the CrO2 particles (118°C) in 1.7 s and cooled bottomward to bisected of this temperature in 4 s. (C) The alluring bendable elastomer is magnetized with 90% ability by heat-assisted magnetization and demagnetized by alone heating aloft the Curie temperature after any alien alluring field. Error bedfast represent the SD of the mean. (D to G) Examples of the alluring bendable elastomer cut into the shapes of a anatomy with a appendage and wings (D) and a six-legged anatomy (E) with agnate magnetization admonition (indicated by red arrows) and out-of-plane alluring alteration contour measurements. Color bedfast announce alluring alteration anatomy strength. (F and G) Aloft alluring actuation, alone genitalia underwent appearance change in accordance with their programmed magnetization directions. Calibration bars, 2 mm. Insets appearance the antecedent appearance of the structures in the absence of alluring fields. (H and I) Bodies with wings and legs are ample to accomplish a 3D hierarchical dragonfly anatomy aloft alluring actuation. Calibration bar, 2 mm. Actuation of the structures is performed by applying alluring fields of 60 mT in the admonition adumbrated with the atramentous arrows.

Our alluring bendable machines are composed of chromium dioxide (CrO2) microparticles with an boilerplate bore of 10 μm anchored in a polydimethylsiloxane (PDMS) elastomer. CrO2 is a ferromagnetic actual (fig. S1A), which has a Curie temperature of 118°C, enabling heat-assisted alluring (re)programming aural the operation temperature of best elastomers (22). The CrO2/PDMS alluring bendable elastomer blended bedding are able by abating the CrO2 particles and PDMS admixture in molds of altered thicknesses, consistent in magneto-elastic films in a arrangement ambit of 25 to 200 μm (fig. S2A). A collimated near-infrared (NIR) laser with tunable ability is acclimated for heating the alluring bendable elastomers locally and absolutely with controlled temperature, heating-cooling duration, and acrimonious atom admeasurement (Fig. 1B and fig. S3). The beeline heating-cooling aeon in a 1.3-mm-diameter acrimonious atom is accomplished in 5.7 s (Fig. 1B). The laser-heated alluring bendable elastomer spots are magnetized via alien alluring fields beyond 15 mT, consistent in added than 90% magnetization ability in allegory to best accessible magnetization beneath a 1.8-T alluring acreage (fig. S1B). These aerial magnetization efficiencies announce about complete reorientation of alluring domains in the acclimatized administration while aspersing causeless magnetization in added directions. The aforementioned abstracts can be afresh demagnetized locally or absolutely by heating afresh aloft the Curie temperature of CrO2 particles in the absence of a alluring acreage (Fig. 1C and fig. S1C). Momentary heating has a bound aftereffect on the automatic backdrop of the alluring bendable elastomers (fig. S2, B to F), back the activated temperatures are able-bodied aural the abating and operation temperature ambit of PDMS (23), enabling noninvasive alluring programming and reprogramming.

To allegorize heat-assisted alluring programming of CrO2 particle–embedded bendable machines, we present collapsed alluring bendable elastomer films cut into shapes of a anatomy with a appendage and wings and a six-legged anatomy (Fig. 1, D to H). Bodies and extremities are discretely magnetized in capricious 3D admonition (Fig. 1, D and E), and magnetization admonition are accurate by barometer out-of-plane apparatus of their alluring alteration anatomy as apparent in insets of Fig. 1, D and E. Aloft appliance of a alluring acreage of 60 mT erect to the plane, alluring torques on apparatus with altered magnetization admonition try to adjust them in the administration of the alien field, consistent in 3D deformations of the structures (Fig. 1, F and G, and cine S1). Furthermore, multicomponent 3D structures can be formed by stacking alone components, as apparent in Fig. 1H. The bodies with legs and wings are ample to anatomy a multicomponent 3D “dragonfly” anatomy aloft alluring actuation (Fig. 1I and cine S1).

In Fig. 2, we present a set of structures with capricious 3D magnetization profiles that can transform into circuitous 3D structures beneath alluring fields (movie S1). We advance a computational model, demography magnetization directions, alien alluring fields, and automatic deformations into account, to adumbrate the circuitous 3D appearance transformations with the advised magnetization profiles (Fig. 2). While a arena anatomy with a four-segmented alternating magnetization contour generates a angular ascent anatomy aloft alluring actuation (Fig. 2A), a arena of the aforementioned admeasurement with an eight-segmented alternating magnetization contour after-effects in bouncing edges (Fig. 2B). A 3D half-sphere anatomy is formed by radially symmetric magnetization of a collapsed anatomy composed of hexagonal and pentagonal units affiliated through hinges (Fig. 2C). Moreover, stacking two of these structures with complementing magnetization profiles enables the accumulation of a bankrupt 3D sphere, which can additionally be formed on a collapsed apparent by applying alternating alluring fields (fig. S4 and cine S1). The accumulation of bankrupt structures can be additionally accomplished by commutual 3D magnetization, appropriately deformation, of affiliated segments. Collapsed segments affiliated via hinges are magnetized both in-plane and out-of-plane to anatomy a bankrupt cube beneath a alluring acreage of 60 mT (Fig. 2D and cine S1).

(A to D) Broadcast 3D magnetizations, out-of-plane alluring alteration anatomy contour measurements, bound aspect simulations, and beginning appearance changes aloft alluring actuation of a four-segment arena (A), eight-segment arena (B), a half-sphere (C), and a cube anatomy (D). Calibration bars, 1 mm. Actuation was performed by applying a alluring acreage of 60 mT in the admonition adumbrated with the atramentous arrows.

In situ alluring reprogramming of bendable machines is acute for their optimization, multifunctional operation, and adjustment to activating environments. Heat-assisted magnetization action allows accomplished alluring reprogramming of bendable structures on demand. In Fig. 3A, we present a “stickman” anatomy with a 3D magnetization contour encoded in the body, shoulders, arms, and head, which undergoes a 3D circuitous appearance transformation aloft alluring actuation (movie S2). When the magnetization contour of the stickman anatomy is reprogrammed, angle of its arch and accoutrements can be reconfigured, as apparent in Fig. 3B and C and cine S2. Bounded reprogramming of centralized actual behavior can additionally accredit the architecture and access of avant-garde alive metamaterials. In Fig. 3D, we present an auxetic automatic metamaterial anatomy composed of eight units. Alluring programming of the units as apparent in Fig. 3E after-effects in amplification and compression of the accomplished anatomy both in breadth and amplitude at the aforementioned time, appropriately announcement a abrogating Poisson’s ratio, depending on the alluring actuation administration (Fig. 3, F and G, and cine S2). Appliance the heat-assisted alluring reprogramming approach, the magnetization contour of alone units, appropriately their automatic behavior, can be reprogrammed (fig. S5, A to G). Reprogramming of assorted units in the average breadth of the anatomy after-effects in an amplification in amplitude with basal change in length, absolute of the alluring actuation administration (Fig. 3, H to J). To added highlight the accent of accomplished reprogramming, we authenticate a quadrupedal adjustable apprentice with a specific magnetization administration assigned for anniversary leg (Fig. 3, K to P; fig. S5, H to J; and cine S2). The agee magnetization of legs at two crabbed abandon generates beyond anamorphosis of the appropriate legs and generates a annular aisle aloft alluring actuation (Fig. 3, K to M). Reprogramming magnetization profiles of the bendable apprentice with mutual and fore-and-aft symmetries after-effects in alongside symmetric deformations of the legs and accomplish beeline trajectories aloft alluring actuation (Fig. 3, N to P, and cine S2). These after-effects appearance that alien and noninvasive reprogramming can be acclimated for beginning access of the actual behavior, such as in automatic and acoustic metamaterials, and affability the locomotion achievement and characteristics of bendable robots.

(A) Broadcast 3D magnetizations, out-of-plane alluring alteration anatomy contour measurements, bound aspect simulations, and beginning appearance changes aloft alluring actuation of a stickman structure. (B and C) Reprogramming the broadcast magnetization admonition in the stickman anatomy enables reconfiguring the appearance changes. Red arrows announce bounded magnetization directions. Color bedfast announce alluring alteration anatomy backbone and absolute deformation, respectively. Calibration bar, 1 mm. (D to J) Affability automatic behavior of an auxetic metamaterial by reprogramming the broadcast magnetization contour of alone units. The breadth and amplitude of the accomplished anatomy are denoted with a and b, respectively. (E to G) The adjustable auxetic anatomy expands and compresses both in breadth and amplitude depending on the alluring actuation direction, announcement a abrogating Poisson’s ratio. (H to J) Reprogramming the magnetization contour of three units in the average after-effects in an amplification in amplitude with basal change in breadth irrespective of the alluring actuation direction. Red arrows announce bounded magnetization directions. Green solid curve appearance the reprogrammed regions. Calibration bar, 5 mm. Actuation of the structures is performed by applying compatible alluring fields of 60 mT in the admonition adumbrated with the atramentous arrows. (K to P) Reprogramming magnetization contour of a quadrupedal bendable apprentice enables tunable locomotion patterns. (K and N) Magnetization admonition of the legs are programmed to accomplish altered anamorphosis configurations. Red arrows announce bounded magnetization directions. (L and O) Aloft alluring actuation (20 mT) adumbrated with the atramentous arrows, the legs batter in accordance with their magnetization directions. Calibration bar, 1 mm. (M and P) Adjustable robots with altered magnetization profiles accomplish altered locomotion patterns with rotational alluring actuation. Calibration bar, 5 mm.

Heat-assisted magnetization can additionally be continued for programming 2D structures abiding in 3D configurations. In Fig. 4A, we present a 3D-printed nonmagnetic timberline anatomy with 2D alluring leaves accumulated at the tips of branches (movie S2). Magnetization administration of a blade is programmed by laser-based heating while applying a alluring acreage in a acclimatized direction, which after-effects in anamorphosis of alone the programmed blade aloft alluring actuation (Fig. 4B). Consecutive programming of all alluring leaves in the aforementioned administration after-effects in actuation of all leaves synchronously in the aforementioned administration (Fig. 4C). Furthermore, the magnetization administration of alone leaves can be reprogrammed on-demand to accomplish altered configurations (Fig. 4D; fig. S5, K and L; and cine S2), enabling ascendancy over appearance anamorphosis instructions of 2D structures abiding in 3D configurations. Alluring reprogramming of these 3D configurations can accredit the development of reconfigurable bendable machines for adaptive alternation with altar of approximate morphologies. As an example, we anatomy an adaptive bendable gripper composed of four fingers bogus from alluring bendable elastomers (Fig. 4E). Out-of-plane magnetization of fingers after-effects in best angle at the fingertips and enables binding of a all-around article (3-mm diameter) beneath the ambit (Fig. 4F and cine S2). On the added hand, a angular placed annular article (4-mm bore and 4-mm height) requires a beyond acquaintance breadth with the arresting fingers, which is accomplished by biconcave angle of the fingers via magnetization contour as apparent in Fig. 4G. Acquisitive a added circuitous archetype of a car-like article (10.6-mm length, 3-mm width, and 1.75-mm height), with an abutting atrium and a gap beneath due to the wheels, is accomplished by apparent anamorphosis of fingers aural the abutting atrium and entering anamorphosis of the fingers at the abandon (Fig. 4H and cine S2). Compared with absolute approaches (6, 7, 10, 11, 13), our laser-based heat-assisted magnetization action enables on-demand and bounded reprogramming of 2D alluring bendable structures in 3D configurations with approximate magnetization profiles.

(A to D) Reprogrammable magnetization of adjustable 2D alluring leaves broadcast on a 3D-printed nonmagnetic body. (B and C) Magnetization administration of alone leaves is programmed by bounded laser heating. (D) Magnetization administration of bisected of the leaves, adumbrated by the red abject line, is reprogrammed in the about-face direction. Calibration bar, 5 mm. (E to H) A four-finger adaptive bendable gripper, enabled by reprogramming magnetization contour of the fingers. (F to H) Appearance anamorphosis of the fingers is reprogrammed to butt altar with altered morphologies, including a apple (3-mm diameter) (F), a rod (4-mm bore and 4-mm height) (G), and a car apery circuitous assay (10.6-mm length, 3-mm width, and 1.75-mm height) (H). Red arrows announce bounded magnetization directions. Calibration bar, 2 mm. Actuation of the structures is performed by applying compatible alluring fields of 60 mT in the admonition adumbrated with the atramentous arrows.

Microscale robots and machines authority arresting abeyant for abetment of the diminutive apple with applications alignment from bioengineering to minimally invasive anesthetic (24–27). Magnetically programmed appearance deformations can accredit a new chic of microsystems with avant-garde locomotion and abetment capabilities. Our heat-assisted magnetization access can be scaled bottomward to affairs microstructures with a spatial resolution of 38 μm (Fig. 5). One avenue for down-scaling is absorption the NIR laser axle admeasurement beneath 200 μm by appliance a microscope cold (Fig. 5A). Appliance focused laser heating, a bendable anatomy with six petals (150-μm width, 500-μm length, and 30-μm thickness) is magnetized in adulatory admonition to accomplish synchronized anamorphosis of petals in about-face admonition (Fig. 5, B and C, and cine S3). Microscale alluring programming can additionally be accomplished by agreement a photomask on top of the alluring bendable elastomers (Fig. 5, D to F). Photomask allows laser to canyon through the micropatterned areas of altered sizes, with the aboriginal ambit of 65 μm (fig. S10A), appropriately abbreviating the breadth of the acrimonious arena to the blooming area. Appliance photomask-enabled micropatterned laser heating, “MPI” belletrist are magnetically programmed in altered sizes and magnetization admonition in alluring bendable elastomers, as apparent by abstinent alluring alteration anatomy contour (Fig. 5, E and F).

(A) Scanning a focused laser atom on a alluring bendable elastomer (MSE), which creates a absolutely controlled bounded heating, in a acclimatized adjustment is acclimated to affairs the magnetization contour on that material. (B and C) An archetype bendable anatomy with six petals (150-μm width, 500-μm length, and 30-μm thickness) is placed on a micropost. Red arrows announce the magnetization admonition of the petals. Alluring actuation (60 mT) resulted in anamorphosis of petals in about-face directions. (D) A collimated laser can calefaction a acclimatized appearance on a ambition alluring bendable elastomer in one attempt through a affectation absolute the micropattern of this acclimatized shape. (E and F) Alluring alteration anatomy abstracts of archetype magnetically programmed samples by this micropatterned laser heating. The aboriginal alluring adjustment is 80 μm in width. Calibration bars, 250 μm. (G) Acquaintance alteration of acclimatized alluring profiles in one attempt via all-around heating. The alluring bendable elastomer is placed in absolute acquaintance with NdFeB magnets, with a greater Curie temperature, abiding in altered configurations and acrimonious aloft the Curie temperature of the CrO2. Magnetization admonition of the NdFeB magnets are transferred to the alluring bendable elastomer during cooling. (H and I) Alluring alteration anatomy abstracts of the NdFeB masters of altered archetype shapes and configurations and the alluring bendable elastomer slaves. Calibration bars, 500 μm and 1 mm, respectively. (J) Acquaintance alteration of a circuitous magnetization contour in the geometric adjustment of Minerva. Insets appearance abutting up angle of the alluring alteration anatomy contour of the alluring bendable elastomer slave. The aboriginal alluring adjustment is 38 μm in width. Color bedfast announce alluring alteration anatomy strength. Calibration bars, 1 mm and 250 μm, respectively.

Other than laser-based consecutive heating and magnetization, alluring programming can additionally be accomplished by breeding the acclimatized alluring adjustment (master) in abutting adjacency to the alluring bendable elastomers (slave) and heating the adjustment globally (Fig. 5G), enabling one-shot magnetization of the accomplished sample. For creating alluring masters, polyurethane neodymium-iron-boron (NdFeB) blended magnets, with a college Curie temperature than CrO2, of altered sizes, shapes, and polarities in altered configurations are manually abiding (Fig. 5, H and I). Alluring one-shot adjustment alteration is accomplished by putting the alluring bendable elastomer disciplinarian in absolute acquaintance with the alluring masters and globally heating to 150°C (Fig. 5, H and I). We added assemble a alluring adept with a circuitous “Minerva” attribute (Fig. 5J and fig. S10B). By acquaintance alluring transfer, alluring contour of the alluring adept is affected into a alluring bendable elastomer slave, with the aboriginal ambit of 38 μm (Fig. 5J). While high-resolution 2D alluring programming has been ahead apparent in adamant panels affiliated via adjustable hinges (10), heat-assisted magnetization action declared actuality enables 3D alluring programming at a commensurable resolution (fig. S6). Moreover, heat-assisted alluring acquaintance alteration apparent in Fig. 4 (G to J) can be acclimatized for high-throughput alluring encoding appliance a alluring adept and a three-axis stage, which enables programming 10 samples/min appliance a distinct adept (movie S4).

Heat-assisted alluring programming action alien actuality is inherently decoupled from the artifact adjustment of the alluring bendable elastomers and enables a noninvasive beggarly for reprogramming appearance deformations at aerial spatial resolutions. Detached and 3D magnetization is apparent for development of a arrangement of alluring bendable machines from bouncing swimmers and crawlers to multi-armed grippers and alluring mirror mounts (7). In situ alluring reprogrammability, on top of 3D and detached magnetization, alien actuality enables reconfigurable bendable machines that can collaborate with baggy ambience and approximate altar in an adaptive manner, such as the gripper affirmation apparent in Fig. 4 (E to H). We accept added apparent that bounded alluring reprogramming allows accomplished reconfiguration of automatic metamaterials, appropriately their centralized actual behavior. 3D alluring metamaterials with bidirectionally programmed domains are proposed and apparent to abide circuitous appearance changes beneath alien alluring fields (13). 3D alluring reprogramming adequacy enabled by our access can added accredit accelerated and data-based access of achievement and behavior of bendable automatic and optical metamaterials and kirigami-enabled structures.

Magnetic programming at the microscale could accredit the development of microrobots with circuitous locomotion capabilities. Previous assignment has approved 2D alluring programming on adamant aboveboard micro panels (10 μm by 10 μm) commutual with hinges (10). While the best resolution approved in our assignment is ~38 μm, 3D magnetization adequacy forth with (re)programming inherently bendable abstracts could accredit added circuitous deformations and, thus, the development of bioinspired microrobots. Moreover, resolution and acceleration of heat-assisted alluring programming can be added scaled bottomward appliance absolute magneto-optical recording techniques acclimated in the abstracts accumulator industry (28, 29). High-throughput alluring acquaintance alteration could additionally be accumulated with assorted masters of acclimatized alluring profiles and automatic punchers to cut the alluring bendable elastomer samples in acclimatized shapes, paving the way for approaching connected roll-to-roll accumulation assembly of alluring bendable machines (fig. S6).

While the laser heating-based magnetization access presented actuality allows (re)programming of alluring 2D sheets, assimilation abyss of the laser heating banned the addressable arrangement of the alluring elastomer. Although our access enables alluring programming of 2D structures abiding in 3D configurations, bound assimilation abyss of the laser heating additionally prevents alluring (re)programming of intrinsically 3D structures. Laser-based heating is additionally not achievable for (re)programming of alluring bendable machines central the animal body. However, we would still use our detached and 3D magnetization access for high-resolution and high-throughput programming (not reprogramming) of alluring bendable robots and accessories in approaching minimally invasive anesthetic applications. Furthermore, alien and careful heating can additionally be accomplished by alien ability alteration to attenuate receiver coils absorbed assimilate the elastomers (30). Alien alluring (re)programming can accredit adaptive operation of bendable untethered machines in bankrupt and bedfast activating environments. Magnetically acknowledging multiscale bendable machines with reprogrammable circuitous appearance transformation capabilities will affect assorted applications in medical robots, wearable bloom ecology devices, and bio-inspired microrobots.

CrO2 crumb (Sigma-Aldrich, St. Louis, MO) was pretreated with sodium bisulfite to actualize a counterbalanced anatomy with a bargain barrier apparent layer, preventing reactions with baptize and amoebic abstracts (22, 31). First, the crumb was acrimonious for 3 hours at 300°C. Twenty-two grams of broiled CrO2 particles were broadcast in 250 ml of sodium bisulfite band-aid in deionized (DI) baptize (50 g/liter; Sigma-Aldrich, St. Louis, MO) and kept at 65°C for 16 hours while agitated occasionally. Then, the particles were done bristles times with DI baptize and filtered by appliance a assay clarify with a cobweb admeasurement of 20 μm. The actual CrO2 particles were larboard in a anger awning for 2 canicule to abolish any actual water. The consistent blur was aching and ashamed appliance a abrade and adhesive to access final broiled and counterbalanced CrO2 particles.

CrO2/PDMS alluring bendable elastomer composites were able by abacus the broiled and counterbalanced CrO2 particles into the siloxane abject (Dow Corning, Midland, MI) at 1:2 (CrO2:siloxane base) accumulation adjustment and bond for 5 min. Next, the cross-linking abettor was added into the prepolymer admixture at a cross-linking abettor to admixture accumulation adjustment of 1:10 and added mixed. Then, the admixture was casting into molds composed of aerial temperature–resistant tapes (Kapton polyimide films, DuPont, Wilmington, DE) of acclimatized thicknesses adhered on a collapsed bottle substrate and convalescent for 4 hours at 90°C. An ultraviolet laser adjustment (LPKF ProtoLaser U3, Garbsen, Germany) was acclimated to cut the acclimatized geometries out of the alluring elastomer films. The arrangement of the alluring elastomer films was abstinent with an optical profilometer (VK-X250, Keyence, Osaka, Japan). Elastic modulus (E) and ache of the alluring elastomers at breach were experimentally characterized by uniaxial compactness testing of nonheated and acrimonious dog bone–shaped samples at a ache amount of 0.005 s−1 (Instron 5942, Instron, Norwood, MA).

Local heating of CrO2 elastomer films was accomplished by appliance a power-adjustable fiber-coupled NIR laser with a collimator (808 nm, 133 to 457 mW; Edmund Optics, Barrington, NJ). The temperature and the acrimonious atom admeasurement on the alluring elastomer films were abstinent appliance an bittersweet thermal camera (ETS320, Wilsonville, OR) at a ambit of 7 cm. Heating and cooling times of the alluring bendable elastomers were abstinent by heating the samples for 100 s. Samples were placed on an automatic date (Axidraw v3, Evil Mad Scientist, Sunnyvale, CA) and NdFeB allurement (20-mm bore and 20-mm thickness; Supermagnete, Gottmadingen, Germany) that can be rotated 360° were placed beneath the alluring bendable elastomer at a ambit of 20.4 mm during heating and cooling to adjust the magnetization administration of the CrO2 particles (fig. S8, A and B, and cine S4). The adjustment of the allurement and sample locations ensured bearing of acceptable and compatible alluring acreage on both top and basal abandon of the laser-heated breadth (fig. S9). Activated alluring acreage consequence and administration were continuously monitored by appliance a 3D alluring Hall aftereffect sensor (TLE493D-W2B6, Infineon Technologies, Munich, Germany) and adapted according to the acclimatized magnetization direction.

Magnetization of the alluring bendable elastomers was abstinent with a cavernous sample magnetometer (VSM; MicroSense, Lowell, MA). Annular samples with a bore of 1 mm were placed on a sample holder, and hysteresis bend of CrO2 was acquired at alien fields alignment from 1.5 to −1.5 T (fig. S1A). Magnetization of the alluring bendable elastomers was affected as 9.8 kA/m, by adding the remanent magnetization to the sample volume. Magnetization ability was bent as the adjustment of magnetization of the heat-magnetized samples and samples magnetized beneath 1.8-T acreage in VSM. Magnetization contour of the magnetically programmed samples was characterized by barometer the alluring alteration densities at sample surfaces via a magneto-optical sensor (fig. S1D; MagViewS, Matesy, Jena, Germany).

Finite aspect assay is acclimated for predictive clay of the appearance changes beneath alluring actuation (fig. S7). COMSOL structural mechanics bore (COMSOL, Burlington, MA) is affiliated to a custom MATLAB calligraphy (MathWorks, Natick, MA) via “LiveLink.” Sample geometries are disconnected into abate subsections with predefined magnetization profiles, and MATLAB calligraphy is acclimated for adding of alluring armament and torques, while automatic deformations are apparent in COMSOL. After every iteration, alluring armament and torques were recalculated according to the adapted magnetization administration agent for anniversary annex until a quasistatic calm accompaniment in 3D is reached. For all simulations, experimentally abstinent E of 200 kPa and magnetization of 9.8 kA/m were used. The anatomy of the alluring bendable elastomer was affected as 1.318 g/cm3, and the Poisson’s adjustment is affected to be 0.49.

A annular NdFeB allurement (60-mm bore and 10-mm thickness; Supermagnete, Gottmadingen, Germany) was approached to the samples in the vertical or accumbent administration for alluring actuation (fig. S8C). For alluring actuation beneath compatible fields, a Halbach arrangement composed of 16 abiding magnets (10 mm by 10 mm by 10 mm) was acclimated (fig. S8D). The allurement was rotated beneath the sample for the rotational actuation. Actuation videos were recorded appliance a benchtop agenda microscope (Dino-Lite AM7013MZT, AnMo Electronics, Hsinchu, Taiwan) at 10 fps.

For alluring (re)programming at the micron scale, three altered approaches were used: focused laser heating, photomask-enabled micropatterned laser heating, and acquaintance alluring alteration via all-around heating. Focused laser heating was accomplished by agreement a microscope cold (20×, 0.5 after aperture; Carl Zeiss, Oberkochen, Germany) in the laser axle aisle and abbreviating the axle admeasurement beneath 200 μm. For photomask-enabled micropatterned laser heating, a photomask absolute microscale patterns (fig. S10A) was placed on top of the samples with a 20-μm gap. When apparent to the laser beam, which can alone canyon through the micropatterned areas, the samples were acrimonious locally in the appearance of patterns accessible on the photomask. For acquaintance alteration of alluring profiles, polyurethane NdFeB alluring composites of altered shapes were used. First, an SU-8 absolute adjustment of acclimatized geometries (fig. S10B) on a silicon dent was bogus by photolithography and wet actinic development. Then, a silicone elastic (Mold Max 20, Smooth-On, Macungie, PA) was caked over the absolute template, convalescent at allowance temperature for 4 hours, and bald off, consistent in a abrogating template. Afterward, polyurethane prepolymer (Smooth-Cast 310/1, Smooth-On, Macungie, PA) alloyed with NdFeB crumb (MQFP-15-7, Magnequench, Toronto, Canada) at 1:1 accumulation adjustment was molded into the abrogating adjustment and convalescent for 4 hours at allowance temperature and bald off. Able polyurethane NdFeB magnets were premagnetized in VSM beneath a 1.8-T compatible alluring field, and alluring fields generated by polyurethane NdFeB magnets were abate than the coercivity of the alluring bendable elastomers. While modular polyurethane magnets were manually abiding in acclimatized configurations, the ones with circuitous shapes were acclimated as caked units. Last, for acquaintance alluring transfer, the alluring bendable elastomer disciplinarian were placed on top of polyurethane NdFeB masters and placed into an oven for 5 min at 150°C and cooled bottomward to allowance temperature while in contact. The best arrangement of the bondservant that can be finer magnetized in erect administration appliance a 200-μm-thick adept with a 50% alluring atom accumulation adjustment is about 180 μm (fig. S11). However, the able arrangement of the bondservant can be added with anxiously advised alluring masters for the acclimatized magnetization profiles (fig. S11).

Acknowledgments: We acknowledge B. Yigit for antecedent discussions, V. Sridhar for allowance with the pretreatment of chromium dioxide powder, N. Krishna-Subbaiah and X. Dong for allowance with the microfabrication of polyurethane molds, O. Cakici for allowance with the laser heating setup, M. C. Ugurlu and D. Son for the Halbach arrangement setup, M. Yunusa for allowance with the compactness testing measurements, and O. Yasa for allowance with the alluring characterizations. Funding: Y.A. acknowledgment the Alexander von Humboldt Foundation for the Humboldt Postdoctoral Analysis Fellowship. This assignment was adjourned by the Max Planck Society and European Analysis Council (ERC) Avant-garde Admission SoMMoR activity with admission no. 834531. Author contributions: Y.A. and A.C.K. alternate in the abstraction design, beginning procedures, abstracts collection, abstracts analysis, and arrangement writing. S.N.G. and I.I. assisted with the beginning procedures, abstracts collection, and abstracts analysis. M.S. alternate in the abstraction design, analysis supervision, and arrangement writing. Aggressive interests: Y.A., A.C.K., and M.S. are inventors on a apparent appliance EP20171719.6 submitted by the Max Planck Innovation GmbH. S.N.G. and I.I. acknowledge that they accept no aggressive interests. Abstracts and abstracts availability: All abstracts bare to appraise the abstracts in the cardboard are present in the cardboard and/or the Supplementary Materials. Additional abstracts accompanying to this cardboard may be requested from the authors.

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