Frequency‐Division‐Multiplexed Microwave Tactile Sensor Array

ABSTRACT Achieving tactile perception with minimal signal crosstalk remains a pivotal challenge in advancing electronic skins, which are frequently plagued by complex wiring. Herein, a spatial pressure sensing system is developed based on a microstrip direct fed spiral resonator array. Leveraging the RF perturbation mechanism and frequency division multiplexing (FDM), this design enables independent signal readout via a single feed line. Unlike traditional matrix addressing requiring complex M+N electrode networks, this architecture utilizes a constant two electrodes, thereby fundamentally simplifying system integration. Furthermore, a sandwich‐structured flexible composite dielectric with unique microstructures and an ionogel is engineered to enhance sensitivity. Consequently, the sensor demonstrates a broad sensing range of 0–150 kPa, exhibiting sensitivities of 0.86 MHz kPa − 1 (<25 kPa) and 0.06 MHz kPa − 1 (>25 kPa) with high linearities. Notably, the device features rapid response/recovery times (71.4 ms), a 25 Pa detection limit, and robust cyclic stability (>1000 cycles). Ultimately, integrated into a robotic fingertip, the sensor accurately identifies and digitally reconstructs planar topographies. This work provides a highly scalable RF sensing strategy for developing high spatial resolution, low‐crosstalk e‐skins.