Geometric analysis and simulations give design rules for a scale structure: friction above a threshold hinders morphing, and reshaping the scales’ surface eases the trade-off between morphing and stiffening.

A computational model of gradient nanograined copper shows that its coarse-grained core makes shear bands form early and multiply at the surface, explaining its ductility.

Simulations show that a metal substrate makes a thin metallic glass film form many shear bands instead of one, which raises its tensile ductility.

Simulations show that a substrate whose grains coarsen with depth can let a thin film stretch further before necking than a uniform coarse-grained substrate does.

Bistable joints modeled on natural sutures let metamaterials built from particles morph and then hold their shape under load without continuous actuation.

Tessellated particles joined by shape memory alloy springs change shape and stiffen together when heated electrically.

A thin, soft impedance sensor that conforms to skin reads the contractions of several deep muscles, for gesture recognition, force prediction, human-robot collaboration and exoskeleton control.

Silicone actuators bend under vacuum in directions set by the layout of their holes, and drive grippers and a crawling robot.

Building blocks that snap between two stable shapes form a robot arm and a tube crawler that hold their shapes when the air supply is cut.

Rigid tiles linked by actuated fibers form fabrics that switch from soft to stiff around the body, for exosuits and body armor.

A design method divides a curved 3D surface into rigid particles laid out flat, which tendons pull into that shape with tunable stiffness.

Rigid particles held by prestressed soft ligaments form beams whose bending load capacity is set by particle shape and prestress, and can be tuned by electrical heating.

A droplet energy generator coated on a recycled DVD turns single falling droplets into electricity for self-powered environmental sensors.

A flexible capacitive skin senses both touch pressure and approaching objects, and can tell metals, polymers and human skin apart before contact.

Rigid particles sealed in a rubber envelope form structures that change shape and stiffen under vacuum, and sense their own deformation through conductive coatings.

Finite element scratch tests show why bimodal nanograined copper has lower friction than uniform copper: its mixed grain sizes restrain strain localization.

Finite element scratch tests show that gradient nanograined copper has lower friction because its layers deform together and spread the strain.

Copper–zirconium nanolayers with graded spacing deform compatibly in micropillar compression, removing the mismatch between their soft and hard layers.