Piezoelectric paper for physical sensing applications

We have developed robust and mechanically flexible piezoelectric paper. The fabrication process involves functionalization of barium titanate (BaTiO3) nanostructures onto wood fibers, followed by activation in a suspension of the commercially available paper-strength-enhancing additive, carboxymethyl cellulose (CMC), which improves fiber-fiber bonding. This leads to piezoelectric paper with both high tensile strength and flexibility. We have investigated the effect of CMC concentration (2–6 wt%) on the tensile properties of the paper and found the highest tensile strength at 6wt% CMC. This piezoelectric paper has the largest piezoelectric coefficient reported for paper to date (d 33 = 37 − 45.7 ± 4.2 pC/N) and is comparable to that of commercially available piezoelectric polymers such as polyvinylidene fluoride with d 33 = 30 pC/N. In addition, we have demonstrated the application of this paper as a tactile sensor.