In this study, a 0-3 piezoelectric composite based on lead zirconate-titanate (PZT)/polyvinyl-butyral (PVB) was fabricated and characterized for its potential application in tactile sensing. The 0-3 composite was developed to incorporate the advantages of both ceramic and polymer. The paste of 0-3 PZT–PVB composite was printed using a conventional screen-printing technique on alumina and mylar substrates. The thickness of the prepared composite was approximately 80 μm. After printing the top electrode of the silver paste, 10 kV/mm of DC field was applied at 25 °C, 120 °C, and 150 °C for 10 min to align the electric dipoles in the composite. The piezoelectric charge coefficient of $d_{33}$ and the piezoelectric voltage coefficient of $g_{33}$ were improved by increasing the temperature of the poling process. The maximum values of $d_{33}$ and $g_{33}$ were 14.3 pC/N and 44.2 mV·m/N, respectively, at 150 °C. The sensor’s sensitivity to the impact force was measured by a ball drop test. The sensors showed a linear behavior in the output voltage with increasing impact force. The sensitivity of the sensor on the alumina and mylar substrates was 1.368 V/N and 0.815 V/N, respectively. The rising time of the sensor to the finger touch was 43 ms on the alumina substrate and 35 ms on the mylar substrate. Consequently, the high sensitivity and fast response time of the sensor make the 0-3 PZT–PVB composite a good candidate for tactile sensors.

Stretchable strain sensors are capable of acquiring data when in contact with human skin or equipment and are widely used in wearable applications. Most strain sensors have tensile properties of less than 20% and have limitations regarding body motion linkage, complex sensor structure, and motion nonreliability. To address these problems, we developed a high tension and high sensitivity sensor with a gauge factor over 40 and tensile stress about 50%. Polydimethylsiloxane (PDMS) was selected as the flexible substrate to ensure tensile strength, and polyaniline (PANI) was used to measure the resistance changes in the sensor. In particular, problems regarding poor uniformity of PANI on PDMS were resolved by surface treatment of the PDMS, wherein PANI polymerization was performed sequentially after forming a self-assembled monolayer (SAM) on the PDMS substrate. O₂ plasma and (3-aminopropyl)triethoxysilane were used to form the SAM. It is expected that this sensor can obtain stable characteristics even under high tensile stress through the evenly formed PANI films on the surface-treated PDMS substrate and may be used in various flexible sensor applications.