Stretchable Piezoelectric Tensile Sensor Patterned via Ultraviolet Laser Cutting

This paper reports a piezoelectric dynamic tensile sensor comprising a metalized polyvinylidene fluoride (PVDF) film patterned with fractal curves and encapsulated in polydimethylsiloxane (PDMS). Because of the high precision and low peripheral heating of the UV laser process, we could achieve a PVDF linewidth down to 600 μm with single step cutting while maintaining piezoelectric functionality. With a second-order fractal curve, our PVDF sensor is omnidirectionally stretchable. In tensile tests using a linear slider, we found this sensor showed good dynamic sensitivity, detecting extension rates down to 5 mm/s. UV laser cutting provides a simple, fast and cheap fabrication process for stretchable piezoelectric devices including low-power sensors and wearable energy harvesters. The fabrication process and the device are highly compatible with rapidly developing stretchable self-powered systems.