We are developing various stretchable sensor devices based on nanomaterials that are stable under applied stain; stretchable
gas and UV sensor, pressure/strain sensor, sound sensor, and temperature sensor.
As a NO2 gas sensor, composite film of SnO2 nanowires and multi-walled carbon nanotubes (MWNTs) and patterned graphene
were used where the increase of hole concentration upon adsorption of NO2 gas induced the increase in current. SnO2 nanowires
exhibited e-h pairs upon exposure to UV lights with energy higher than the bandgap of SnO2. The change of contact resistance
between the top layer of Au-coated PDMS micropillars and the bottom layer of polyaniline nanofiber film was measured with
variation of the applied pressure. Fragmentization of graphene foam could increase the sensitivity of the strain sensor with
increase in the resistance under applied strain. For the first time, stretchable sound sensor could be demonstrated via interaction
between Neodymium (Nd) magnet and liquid metal (Galinstan) coil embedded in a flexible polymer substrate.
Active matrix-based temperature sensor was also constructed with polyaniline nanofibers. Those sensors exhibited mechanical
stability in performance under deformations.