Paper-based hygrosensor and hygromotor

This invention exploits the use of paper as the basis for sensors and actuators that respond to a gradient in humidity. It is envisioned as a hyper-low cost smart material platform, in a range of biomedical and commercial applications. The key innovation is harnessing a large mechanical response, that’s reversibly and predictably caused by a moisture gradient near an evaporative surface. As a sensor in moist microclimates, an initially flat piece of paper is fixed at one edge as a cantilever. When exposed to a humidity gradient, the paper will bend away from the more humid side, due to uneven expansion through the thickness of the paper. As a hygromotor, the invention can generate symmetric, periodic, oscillation or directed motion.

Intellectual Property Status: Patent(s) Pending