Transparent piezoelectric actuators for haptic
Published : 12 March 2020
The haptic technology (science of touch) is in full rise and attracts more and more interest from industrials in the fields of telephony or automotive. Piezoelectric actuators are used to generate vibrations on a tactile surface to produce a haptic feedback, thus facilitating (or augmenting!) interactions between the user and his environment. Some tactile surfaces, such as screen, dashboard or window, would ideally require the use of transparent actuators. However, thin film piezoelectric actuators are deposited on a silicon substrate and incorporate non-transparent layers (electrodes, etc.). Strong technological constraints, such as the crystallization temperature of the piezoelectric material (around 700 °C for the PZT), make the thin film deposition of transparent piezoelectric stacks on glass particularly complex, or impossible. LETI has recently developed an innovative technology for transferring one or more layers, for example PZT, from a silicon growth substrate to a host substrate such as glass (several patents).
The objective of this thesis will be to design and realize transparent piezoelectric actuators on glass substrate for a haptic application. A state of the art on the subject will make it possible to establish the targeted specifications for the chosen device. Based on the knowledge and expertise available at LETI, the PhD student will work on the integration of materials (piezoelectric, electrodes, etc …) allowing in particular obtaining a functional stack with the required transparency, as well as on the design and the realization of the actuators and their characterizations.