Kirigami piezoelectric actuators

Introduction

Piezoelectric materials can be used for both sensing of mechanical sources as well as actuation to create a displacement in your application. The era of thin-film electronics opened new application domains in this field, with for example micro-mirrors or nano-motors as examples. Piezoelectric materials can efficiently create a high stress even in thin layers, a stress that can be tuned by the applied voltage. The challenge with piezoelectric materials is to translate this stress in a large movement, using some leveraging mechanism. The piezoelectric platform (compatible with large glass sheets) developed at imec uses highly efficient thin-film piezoelectric materials that can be deposited on large flexible substrates. By creating a cut pattern in this flexible substrate, following a kirigami structure, complex movements and large displacements can theoretically be achieved.

Topic

The purpose of this PhD is to demonstrate a kirigami based actuator using piezoelectric thin films as the actuation method. From the start of the PhD, a piezoelectric platform on flexible substrates is available, processed in our imec cleanroom labs. While a high piezo response is achievable on this platform, a way to leverage the generated stress into movement has to be developed by design. Further adaptations of the process flow (eg change the used flexible substrate) can further improve the displacement of the kirgami actuator. Finally, a demonstration and characterization these kirigami actuators is envisaged. This PhD has three important pillars: 1) simulations of piezoelectric kiragami elements for optimized performance; 2) process adaptations to create large displacement and 3) characterization of the element. The PhD student will be involved in the entire fabrication cycle (design, processing and characterization) performed in the state-of-the-art facilities including imec's cleanroom and dedicated thin-film labs. The options that we have available in technology combined with the large options in mask design, offer large opportunities for creative innovations in this PhD topic.

The candidate

You are a highly motivated recent graduate holding a Master’s degree in nano-engineering, physics, material science, electrical engineering, or related. You have an interest in the processing of thin-film semiconductors, mechanical effects in such layers, and electrical and mechanical characterization. You will be expected to work safely in a cleanroom environment and acquire processing and lab skills. It is expected that you will present results regularly.  You are a team player and have good communication skills as you will work in a multidisciplinary and multicultural team spanning several imec departments. Given the international character of imec, an excellent command of English is a must.