ABSTRACT The present study focusses on the innovative design of a multimaterial pressure sensor with a soft sensing core and soft electrodes. In the first part of the work, nanocomposites based on low‐stiffness poly(dimethylsiloxane) (PDMS) and different fractions of single‐walled carbon nanotubes (CNTs, from 0.15 to 0.5 wt.%) are tested electromechanically to assess piezoresistivity and stiffness. In the second, the design of the sensor is described. It features an innovative architecture with liquid‐metal electrodes placed on the sides of the sensing nanomaterial. This alignment enhances sensitivity and induces monotonicity by coupling constructively the geometric and resistivity components of the piezoresistive response. Fabrication by stepwise molding is demonstrated trying two outer shells of different stiffness, and then various pressure sensors are produced with the best‐performing sensing nanomaterials, before being characterized and compared. We highlight the innovative characteristics of the proposed sensors in terms of electrode material architecture and positioning, simple design and fabrication, integral softness and low stiffness (< 1 MPa), appreciable linearity up to 0.0105 (Ω/Ω)/kPa, mid‐high working stresses in the 0–210 kPa range, and recoverable compressive strains up to 43%. The reduced bandwidth of the sensor suggests applicability in the detection of pressure changes rather than the measurement of pressure values.
Lazzari et al. (Thu,) studied this question.