Embroidering Resonant Circuits for Inductive Pressure Sensing

In this paper, we introduce an embroidered resonant circuit for textile-based inductive pressure sensing. By embroidering enameled wire onto a flexible textile, we create a coil and a capacitor using a single continuous wire. This resonant circuit, combined with a ferromagnetic layer and a soft, compressible material such as foam, forms the basis of a flexible and soft pressure sensor. We investigate the fabrication of coils and capacitors through embroidery, evaluate different conductive materials for altering the circuit’s resonance frequency, and assess the impact of different foams on the sensor’s performance. Following our tests, we evaluated an embroidered sensor with a diameter of 45 mm, actuated with a force of up to 50 N over 100 cycles, using foams with different compression strengths. A series of applications demonstrate that our approach offers a performant complement to existing sensing methods used in electronic textiles.