PT  - JOURNAL ARTICLE
AU  - Keplinger, Christoph
AU  - Sun, Jeong-Yun
AU  - Foo, Choon Chiang
AU  - Rothemund, Philipp
AU  - Whitesides, George M.
AU  - Suo, Zhigang
TI  - Stretchable, Transparent, Ionic Conductors
AID  - 10.1126/science.1240228
DP  - 2013 Aug 30
TA  - Science
PG  - 984--987
VI  - 341
IP  - 6149
4099  - http://science.sciencemag.org/content/341/6149/984.short
4100  - http://science.sciencemag.org/content/341/6149/984.full
SO  - Science2013 Aug 30; 341
AB  - A range of stretchable, conductive materials can be made either by making an electrical conductor more stretchable or by adding an electrical conductor to a stretchable material. Keplinger et al. (p. 984; see the Perspective by Rogers) have added to the possibilities of an alternative stretchable ionic conductor based on a hydrogel material used to make deformable devices that are fully transparent to light over the visible spectrum and that can withstand high voltages and high frequencies. 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.