Biodegradable additive manufactured ferroelectret as mechanical sensor

Ferroelectrets are piezoelectric polymers, typically cellular polymer foams that exhibit a large piezoelectric response. In this work, we present a biodegradable 3D printed ferroelectret using Fused Deposition Modeling (FDM). Even though the charging process of the ferroelectret is conducted at room temperature, the printed PLA exhibits good charge stability over 150 days at this temperature. A distinctive feature of the manufactured ferroelectret is that its mechanical properties mainly depend on its geometry, offering the possibility for it to be softer than the printed material itself. In fact, the investigated geometry in this paper exhibits a Young’s modulus of 0.5 kPa for stresses under 1 kPa. An excellent piezoelectric coefficient of 600 pC/N was recorded, which is comparable with the well known polypropylene ferroelectret. The presented ferroelectret is suitable for various mechanical sensor application.