Dealing with 1/f noise in MEMS electrothermal sensing

Electrothermal sensing has been under investigation as a viable means of measuring displacement in micromachined transducers. Compared with capacitive sensors, electrothermal sensors have the advantage of being realizable with an extremely small footprint, which makes them very attractive in MEMS. These sensors are prone to 1/f noise, and therefore are inferior to their capacitive counterparts at very low frequencies. We propose a novel read out circuit and illustrate that it can achieve a significant reduction in the noise associated with electrothermal sensors.