In
work reported in Science (August 20, 2013) a Harvard MRSEC team led by Suo and Whitesides developed a transparent “ionic skin,” a sensor skin
using ionic conductors. It senses signals with high stability and wide dynamic
range, from a gentle touch of a finger to strains over 500%. The new ionic skin
has attributes required for biocompatibility in medical devices and
transparency for use in tunable optics. (a)
As a demonstration, the electrodes were tin-plated copper, the ionic conductors
were a salt-containing hydrogel, and the dielectric was an acylic elastomer
(VHB). VHB was also used to cover the
faces of the ionic skin. (b) The
ionic skin was attached to a straight finger. (c) When the finger bent, the ionic skin stretched. (d) As the finger bent cyclically, the
capacitance changed accordingly. ‘B’ denotes bent finger, and ‘S’ denotes
straight finger. (e) The ionic skin
was transparent. The scale bars in b, c,
e are 2 cm.
