In-Air Long-Range Environmental Temperature Sensing with A Single Scandium-Doped Aluminum Nitride pMUT Array

This paper presents, for the first time, in-air long-range temperature sensing by ultrasound using a single Scandium-doped (15%) Aluminum Nitride (ScAlN) pMUT array. The proposed temperature pulse-echo sensing setup can achieve an impressive 97% accuracy (and a respective average absolute error of 1.4°C) in temperature sensing at 30cm (corresponding to 60cm of round-trip distance) for temperatures up to 90°C. This is accomplished using a single 9mm
²
die without any signal pre/post-amplification with a range that could comfortably be extended to 1m.