Acoustic haptic technology adds touch sensations to human-machine interfaces by integrating piezoelectric actuators onto touchscreens. Traditional piezoelectric haptic technologies use opaque lead-containing ceramics that are both toxic and visible. We have developed a highly transparent lead-free piezoelectric haptic device using potassium sodium niobate (KNN) and transparent conductive oxide thin films. The KNN film, grown on glass, exhibits a pure perovskite phase and a dense microstructure. This device achieves up to 80% transmittance, surpassing lead zirconate titanate (PZT) thin films. It generates an acoustic resonance at 16.5 kHz and produces a peak-to-peak displacement of 1.0 um at 28 V unipolar, making it suitable for surface rendering applications. This demonstrates the potential of transparent lead-free piezoelectric actuators as an effective alternative to conventional PZT haptic actuators.
@article{arxiv.2410.15788,
title = {Highly Transparent Lead-Free Piezoelectric Haptic Device},
author = {Longfei Song and Sebastjan Glinsek and Nagamalleswara Rao Alluri and Veronika Kovacova and Michele Melchiorr and Alfredo Blazquez Martinez and Barnik Mandal and Juliette Cardoletti and Emmanuel Defay},
journal= {arXiv preprint arXiv:2410.15788},
year = {2025}
}