Whitesides Group

Existing stretchable, transparent conductors are mostly electronic conductors. They limit the performance of interconnects, sensors, and actuators as components of stretchable electronics and soft machines. We describe a class of devices enabled by ionic conductors that are highly stretchable, fully transparent to light of all colors, and capable of operation at frequencies beyond 10 kilohertz and voltages above 10 kilovolts. We demonstrate a transparent actuator that can generate large strains and a transparent loudspeaker that produces sound over the entire audible range. The electromechanical transduction is achieved without electrochemical reaction. The ionic conductors have higher resistivity than many electronic conductors; however, when large stretchability and high transmittance are required, the ionic conductors have lower sheet resistance than all existing electronic conductors.

This communication describes the design and fabrication of soft tentacles based on micropneumatic networks spatially distributed at the interface of two different elastomers; these composite elastomeric structures enable complex 3D motion of the tentacles. We demonstrate both the range of motion open to these tentacles, and their capability to grip and manipulate objects with complex shapes. We also extend the capabilities of these soft actuators by embedding functional components (for example, a needle for delivering fluid, a video camera, and a suction cup) in them. We further demonstrate that modifying the texture of the surface of the tentacles can improve their adhesion to slippery surfaces.