  Robust strain gauges are fabricated by growing PtSe2 layers directly on top
of flexible polyimide foils. These PtSe2 layers are grown by low-temperature,
thermally-assisted conversion of predeposited Pt layers. Under applied flexure
the PtSe2 layers show a decrease in electrical resistance signifying a negative
gauge factor. The influence of the growth temperature and film thickness on the
electromechanical properties of the PtSe2 layers is investigated. The
best-performing strain gauges fabricated have a superior gauge factor to that
of commercial metal-based strain gauges. Notably, the strain gauges offer good
cyclability and are very robust, surviving repeated peel tests and immersion in
water. Furthermore, preliminary results indicate that the stain gauges also
show potential for high-frequency operation. This host of advantageous
properties, combined with the possibility of further optimization and channel
patterning, indicate that PtSe2 grown directly on polyimide holds great promise
for future applications.
