Large-Sized Micropillars Enable Superior Performance MXene/PDMS Piezoresistive Sensors Toward Accurate Musical Tone...

Here we present a flexible MXene/polydimethylsiloxane (PDMS) piezoresistive sensor featuring large-sized micropillars (hundreds of micrometers), which promote continuous stress transfer and dynamic interfacial contact evolution, thereby alleviating the intrinsic trade-off between sensitivity and detection range. The PDMS micropillar arrays are fabricated using laser-ablated through-hole molds. The micropillar tips preferentially deform under subtle stimuli, whereas the base layer is progressively engaged under increasing loads. This hierarchical deformation mechanism enables continuous resistance modulation over a broad pressure range. Consequently, the sensor delivers a sensitivity of 103 kPa^{- 1} over a wide detection range of 0.6-588 kPa, together with fast response/recovery times (6/20 ms) and robust cyclability (10,000 cycles). Beyond physiological monitoring, the sensor further enables acoustic-vibration detection from the Erhu, a traditional Chinese bowed instrument. Assisted by a one-dimensional convolutional neural network (1D-CNN), a pitch recognition accuracy of 97.5% is achieved. This work provides a structural design strategy for high-performance piezoresistive sensors and establishes a new paradigm for intelligent recognition and acoustic-based human-machine interfaces.