Inkjet-Printed Soft Resistive Pressure Sensor Patch for Wearable Electronics Applications

Soft pressure sensors may find a wide range of applications in soft robotics, biomedical devices, and smart wearables. Here, an inkjet-printed resistive pressure sensor that offers high sensitivity and can be fabricated using a very simple process is reported. The device is composed of a conductive silver nanoparticle (AgNP) layer directly printed onto a polydimethylsiloxane substrate and encapsulated by a VHB tape. The pressure is measured through change in electrical resistance caused by pressure-induced strain in the printed AgNP thin film. The influence of substrate stiffness and thickness on the sensitivity and achieved sensors with an optimized configuration that exhibit highly repeatable response with a sensitivity of up to 0.48 kPa⁻¹ is systematically studied. It is further demonstrated that such a printed soft sensor patch is capable of measuring arterial pulse waveforms or detecting acoustic vibrations under various sound pressure levels. With its simple and low-cost fabrication process and high sensitivity, the inkjet-printed resistive pressure sensor is promising for future biomedical and smart wearable device applications.