Sea urchin-like microstructure pressure sensors with an ultra-broad range and high sensitivity.

Wang, Xiu-Man; Tao, Lu-Qi; Yuan, Min; Wang, Ze-Ping; Yu, Jiabing; Xie, Dingli; Luo, Feng; Chen, Xianping et al. · Nat Commun · 2021

basic_science · Level V

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Abstract

Sensitivity and pressure range are two significant parameters of pressure sensors. Existing pressure sensors have difficulty achieving both high sensitivity and a wide pressure range. Therefore, we propose a new pressure sensor with a ternary nanocomposite Fe<sub>2</sub>O<sub>3</sub>/C@SnO<sub>2</sub>. The sea urchin-like Fe<sub>2</sub>O<sub>3</sub> structure promotes signal transduction and protects Fe<sub>2</sub>O<sub>3</sub> needles from mechanical breaking, while the acetylene carbon black improves the conductivity of Fe<sub>2</sub>O<sub>3</sub>. Moreover, one part of the SnO<sub>2</sub> nanoparticles adheres to the surfaces of Fe<sub>2</sub>O<sub>3</sub> needles and forms Fe<sub>2</sub>O<sub>3</sub>/SnO<sub>2</sub> heterostructures, while its other part disperses into the carbon layer to form SnO<sub>2</sub>@C structure. Collectively, the synergistic effects of the three structures (Fe<sub>2</sub>O<sub>3</sub>/C, Fe<sub>2</sub>O<sub>3</sub>/SnO<sub>2</sub> and SnO<sub>2</sub>@C) improves on the limited pressure response range of a single structure. The experimental results demonstrate that the Fe<sub>2</sub>O<sub>3</sub>/C@SnO<sub>2</sub> pressure sensor exhibits high sensitivity (680 kPa<sup>-1</sup>), fast response (10 ms), broad range (up to 150 kPa), and good reproducibility (over 3500 cycles under a pressure of 110 kPa), implying that the new pressure sensor has wide application prospects especially in wearable electronic devices and health monitoring.