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

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 Fe₂O₃/C@SnO₂. The sea urchin-like Fe₂O₃ structure promotes signal transduction and protects Fe₂O₃ needles from mechanical breaking, while the acetylene carbon black improves the conductivity of Fe₂O₃. Moreover, one part of the SnO₂ nanoparticles adheres to the surfaces of Fe₂O₃ needles and forms Fe₂O₃/SnO₂ heterostructures, while its other part disperses into the carbon layer to form SnO₂@C structure. Collectively, the synergistic effects of the three structures (Fe₂O₃/C, Fe₂O₃/SnO₂ and SnO₂@C) improves on the limited pressure response range of a single structure. The experimental results demonstrate that the Fe₂O₃/C@SnO₂ pressure sensor exhibits high sensitivity (680 kPa⁻¹), 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.