Flexible thermal sensor array on PI film substrate for underwater applications

Fully flexible thermal sensor array was developed for underwater applications. To minimize conductive heat loss to substrate and shorten response time nickel thin film resistors are fabricated on polyimide film substrate. This flexible sensing belt can be applied onto highly curved non-planar surfaces to measure flow with minimal invasion. Polymer compatible micromachining technology with consideration of waterproof coating was developed. Through calibration performed under constant-current excitation, high temperature coefficient of resistance (TCR) and low time constant of sensor were obtained. Hydrodynamic experiments in water channels were carried out, and it indicates dynamic wave flow can be sensed promptly with this sensing belt.