Direct printing of PZT on glass for surface haptics

Lead Zirconate Titanate (PZT) is a leading piezoelectric material for surface haptics actuators due to its high piezoelectric coefficients and broad frequency response. However, current fabrication methods rely on adhesive bonding of bulk PZT to glass substrates, which is inefficient and labor-intensive. In this study, we developed a modified PZT ink formulation for direct printing onto high-temperature-resistant glass with silver (Ag) electrodes. A major challenge in this approach is the high sintering temperature required for PZT, which can exceed the thermal limits of glass. To overcome this, CuO modification enabled low-temperature sintering at 900 °C. while preserving strong piezoelectric performance (d₃₃: 270–310 pC/N, d₃₁: –40 to –50 pC/N). The resulting actuator generated standing Lamb waves at 36 kHz, achieving a displacement of 1.2 µm under a low driving voltage of 10 Vpp. These results demonstrate the feasibility of CuO-modified, ink-printed PZT for efficient, high-performance piezoelectric surface haptic actuators.