A flexible dual‐gate thin‐film transistor‐based tactile sensor array with polarity‐aware encoding for neuromorphic recognition

Abstract Flexible tactile sensing is pivotal for bridging the physical and digital worlds in embodied intelligence, enabling nuanced contact awareness for robotic manipulation and health monitoring. While piezoelectric sensors offer compelling advantages such as self‐powered operation and high dynamic sensitivity, their intrinsically high output impedance makes them highly susceptible to impedance mismatch and parasitic loading in conventional readout architectures, resulting in signal attenuation and rapid charge dissipation. In this work, we report a monolithically integrated flexible piezoelectric tactile sensor array using dual‐gate indium‐tin‐zinc oxide (ITZO) thin‐film transistors. Direct coupling of the piezoelectric sensor to the top‐gate (TG) electrode establishes an impedance‐matched sensing interface with a sub‐micrometer signal path, eliminating parasitic attenuation. The biased bottom‐gate electrode modulates the threshold voltage to convert the TG piezoelectric voltage into enhanced channel currents, producing amplified output voltage without external charge amplification. The resulting active tactile sensor achieves a twofold improvement in sensitivity (), a fast response time of 10 ms comparable to human skin, an ultralow latency below 700 μs, and an extended 4.86 s decay time, enabling quasi‐static sensing that substantially outperforms conventional millisecond‐scale piezoelectric systems. Leveraging the rich spatial information preserved by the prolonged signal retention, we demonstrate the utility of flexible tactile sensor arrays in pulse waveform monitoring and hand gesture acquisition. A polarity‐aware temporal encoding scheme converts the captured tactile inputs into dual‐polarity spike trains, improving gesture recognition accuracy from 83% to 98%, with spiking transformer attention further revealing distinct class‐dependent spatial structures.