Community Research and Development Information Service - CORDIS

Silicon porosity for piezo-electric/optic applications

A novel, accurate and highly sensitive piezo-electric/optic material that is inexpensive in production is expected to revolutionalise electronic device applications that require bending, pushing or pulling.
Silicon porosity for piezo-electric/optic applications
Most of the commonly used devices that provide piezoelectric response are normally based on a hybrid process that involves attachment to and removal from a device. This process is not only extremely complicated in production leading to significant failures, but also significantly expensive in applications.

Until now, silicon, one of the commonly used materials, has not been exploited in piezoelectric device applications, where transformation of electric energy into mechanical is performed. By turning silicon into porous material, it has been proven that it can respond to voltage and light input by changing shape and size.

The piezoelectric device comprises porous silicon etched out of, and in contact with a silicon wafer that bends under application of voltage between the porous silicon and the silicon. Production is based on simple, common and well-established techniques and it is not costly in either small or large quantities.

Similarly, the piezo-optic device responds by a strain induced by illumination of the porous material to the silicon and its bending. There is the possibility of using a mirror at the silicon side of the wafer that can be easily deformed by voltage or light application. These could be used for instance for reduction of optical aberrations.

This innovative material can be easily integrated into silicon manufacture processes using well-established techniques. Additionally, its production is less costly than other currently available devices'. In comparison to other materials, it is more sensitive at high voltages and accurate as there is no hysteresis. The new material has similar weight to the one of metallic and semiconductor materials.

Further collaborations are sought with academic or industrial partners specialised in Micro Electro Mechanical Systems (MEMS) or electro-optics. The aim is to to use this material in applications where bending, pushing or pulling of a device is required.

Related information

Record Number: 82341 / Last updated on: 2006-01-23
Domain: Energy