Make it stretch, make it glow: The skins of some cephalopods, such as the octopus, are highly flexible and contain color-changing cells. These cells are loaded with pigments that enable rapid and detailed camouflaging abilities. Larson et al. developed a stretchable electroluminescent actuator. The material could be highly stretched, could emit light, and could also sense internal and external pressure. A soft robot demonstrated these combined capabilities by stretching and emitting light as it moved. Science , this issue p. 1071

Stretchable optical waveguides can sense curvature, elongation, and force in a prosthetic hand.

Colorful changes: Distributed fiber-optic sensors have been used for monitoring mechanical deformations in stiff infrastructures such as bridges, roads, and buildings, but they either are limited to measuring one variable or require complex optics to measure multiple properties. Bai et al. now demonstrate dual-core elastomeric optical fibers, one of which contains patterned dye regions. The waveguides are fabricated by molding out of commercially available elastomers and integrate a clear core and an adjacent core doped with up to three macroscale dye regions. Changes in optical paths in the two cores detect deformation and map it onto a color space. By monitoring changes in the color and intensity in both elastomer-based fibers, the researchers could distinguish bending, stretching, and localized pressing with a spatial resolution down to ∼1 centimeter. Science , this issue p. 848

3D texture morphing for camouflage: Some animals, such as cephalopods, use soft tissue to change shape reversibly for camouflage and object manipulation. Pikulet al.used fixed-length fiber mesh embedded in a silicone elastomer to transform a flat object into a 3D structure by inflating membranes (see the Perspective by Laschi). Painted models of rocks and plants were also created that could be morphed to fully blend into their surroundings.Science, this issue p.210; see also p.169