“One-Step” Preparation Process for the Flexible and Breathable Piezoelectric Sensor

One of the key problems restricting the development and application of flexible piezoelectric sensors is the lack of efficient, simple, and low-cost manufacturing processes and equipment. The resulting devices also have certain limitations in material selection and performance that cannot be overcome. Herein, we innovatively propose to combine the traditional extrusion additive manufacturing and electrospinning process to realize the "one-step" preparation of the functional layer, electrode layer, and packaging layer of the flexible piezoelectric sensor. The obtained sensor has the characteristics of softness, breathability, and waterproofness. Specifically, the thermoplastic polyurethane (TPU)/poly(dimethylsiloxane) (PDMS) composite nanofiber mats by electrospinning were packaging layers. Under the support of electrospinning self-encapsulation, TPU/PDMS mats give the piezoelectric sensor outstanding waterproofness and air permeability. Compared with the traditional preparation methods, this method not only avoids the complexity of multistep manufacturing and manual assembly, facilitating automation processing and mass production, but also endows the sensor with good linearity, high sensitivity (1.7 V/N), fast response time (18 ms), excellent air permeability (400 g/m2/day), and outstanding waterproofness. This method provides a method and idea for the manufacture of comfortable, breathable, and waterproof wearable devices.