Plant-based materials give ‘life’ to tiny soft robots

Science Daily   October 23, 2023 Introducing anisotropic properties, and shape-change programmability to responsive hydrogels promises a host of opportunities in the development of soft robots. An international team of researchers (Canada, Germany) synthesized pH-responsive hydrogel nanocomposites with predetermined microstructural anisotropy, shape-transformation, and self-healing. They were largely composed of zwitterionic monomers and asymmetric cellulose nanocrystals. While the zwitterionic nature of the network imparted both self-healing and cytocompatibility to the hydrogel nanocomposites, the shear-induced alignment of cellulose nanocrystals rendered their anisotropic swelling and mechanical properties. They utilized a cut-and-paste approach to program reversible, and complex deformation into the hydrogels. As a proof-of-concept, […]

Resilient bug-sized robots keep flying even after wing damage

Science Daily  March 15, 2023 Although robots driven by rigid actuators have demonstrated agile locomotion and manipulation, most of them lack animal-like robustness against unexpected damage. Dielectric elastomer actuators (DEAs), a class of muscle-like soft transducers, have enabled nimble aerial, terrestrial, and aquatic robotic locomotion. However, unlike muscles, DEAs suffer local dielectric breakdowns that often cause global device failure. Researchers at MIT developed DEAs that can endure more than 100 punctures while maintaining high bandwidth and power density sufficient for supporting energetically expensive locomotion such as flight. They fabricated electroluminescent DEAs for visualizing electrode connectivity under actuator damage. When the […]

World’s fastest exfoliation of material has potential use for photoactuator production

Phys.org  April 19, 2021 Researchers in Japan found that under irradiation with UV light crystals of a photochromic diarylethene peels off into micrometer sized crystals at a speed of 260 microseconds. These crystals can be potentially applied to macroscopic photomechanical actuators rapidly driven based on molecular machinery. As the material returns to its former molecular structure when exposed to visible light, the exfoliation method positions itself as a candidate for photoactuator manufacturing. A machine made up of photoactuators would not need direct contact with the power source to move. Among its many possible functions, it could be accurately manipulated within […]

New on/off functionality for fast, sensitive, ultra-small technologies

Science Daily  September 15, 2020 Actuation at micro- and nanoscale often requires large displacements and applied forces. An international team of researchers (Italy, Japan) has developed an ultra-small actuator based on vanadium oxide crystals that can be turned on and off in a fraction of a millisecond and exhibits nanometer-scale position control. The device is thermally activated through heating just above room temperature to trigger the VO2 crystalline symmetry change associated with the metal–insulator transition. The large lattice expansion of VO2 phase transition, compared to standard materials, is further amplified by the chevron-type geometry. DC and AC operation of the […]