MESA+ University of Twente
Inorganic Materials Science Group

Nanoscale mechanics of PiezoMEMS

Do you want to work on the Nano-valve for lab-on-a-chip applications? Or rather try to capture environmental vibrational energy to a battery using piezoelectric energy scavengers? Please have a look at this project.

Integration of Oxide Electronics on Silicon

The integration of silicon technology and oxide electronics is of major interest in materials science. Taking advantage of the economics of scale of silicon industry and the remarkable properties of oxide electronics, the best of two worlds can be combined. The SmartPie program within IMS aims on development of thin film PiezoMEMS (Piezo Micro Electro Mechanical Systems) on silicon wafers. These devices use a piezoelectric thin film to convert a physical displacement into an electrical signal (and vice versa). This makes them suitable for application in sensors and actuators. Furthermore these devices allow miniaturization of sensing and actuating methods into the nanometer-scale. Using equipment from nanotechnology (scanning probe microscopy, laser interferometer), these devices can be explored with high resolution.

device

PiezoMEMS device, consisting of a Silicon on Insulator (SOI) wafer and patterned oxide layers.

Nanoscale mechanical characterization of PiezoMEMS

The performance of the PiezoMEMS device is mainly related to composition, crystalline structure and microstructure of the oxide layers. For this project, the piezoelectric layer Pb(Zr,Ti)O3 (PZT) will be studied in detail. The mechanical properties can be explored by Piezo Force Microscopy (PFM), which uses a conducting tip to detect vibrations of a piezoelectric surface. Furthermore, the high resolution of PFM allows the imaging the ferroelectric domains dynamics, i.e. the movement of domains while applying a voltage. Recently, the orientation of PZT has been tuned along 001 or 110 crystal axis. This allows the study of nanoscale mechanical properties as a function of crystal orientation. All in all, this project aims to explore of the accuracy-limits in characterization of PiezoMEMS. This project is suitable as both Bachelor and Master project.

image

Piezo Force Microscopy image (2µmx2µm) of Pb(Zr,Ti)O3. Ferroelectric domains are clearly recognizable, the light and dark regions represent up or down polarized material.

Project is coordinated by Ruud Steenwelle, r.j.a.steenwelle@utwente.nl, tel: 0534892876