New textile could keep you cool in the heat, warm in the cold

Phys.org  April 1, 2020 Researchers in China freeze-spun silk and chitosan, a material from the hard outer skeleton of shellfish, into colored fibers with porous microstructures. They filled the pores with polyethylene glycol (PEG), a phase-changing polymer that absorbs and releases thermal energy. The threads were coated with polydimethylsiloxane to keep the liquid PEG from leaking out. The resulting fibers were strong, flexible, and water-repellent. To test the fibers, the researchers wove them into a patch of fabric and put inside a polyester glove. When a person wearing the glove placed their hand in a hot chamber (122°F), the solid […]

Graphene-based actuator swarm enables programmable deformation

Nanowerk  April 1, 2020 Graphene-based actuators featuring fast and reversible deformation under various external stimuli are promising for soft robotics. However, these bimorph actuators are incapable of complex and programmable 3D deformation, which limits their practical application. Researchers in China fabricated a moisture-responsive graphene actuator swarm that has programmable shape-changing capability by programming the SU-8 patterns underneath with specific geometries and orientations on a continuous graphene oxide film, forming a swarm of bimorph actuators. They achieved predictable and complex deformations including bending, twisting, coiling, asymmetric bending, 3D folding and the combination of them due to the collective coupling and coordination […]