13 February 2014
We work in two main areas: IC design and MEMS. We started working in IC design in 1993, and were mainly involved in the design of low power / low voltage analogue building blocks. This area is obviously challenging and interesting, and its need emerged from the requirement of increased battery autonomy as well as compatibility with low voltage digital technologies. In 2008, we started activity in MEMS and are involved in the design of inertial sensors, resonators, compasses and resonators. We have collaboratively worked with ST Malta and Italy on various MEMS and packaging modelling/design projects.
The work in Electronics Letters relates to the analysis of MEMS devices originally intended for RF application. This paper also takes the same structure which was previously used in its linear region for BPSK mixing/demodulation purposes and examines the non-linear behaviour. The behaviour in the non-linear region is dominated by three equilibrium positions of which one is unstable, hence resulting in a bistable structure. Due to the non-linear region, the design lends itself to a broader range of applications ranging from cryptography to chaotic carrier modulation and even, potentially, to energy harvesting.
Originally, this analysis started from the design of a MEMS BPSK demodulator. Now that the wider potential of this device has become clear, applications motivating further research are those that would benefit from having a structure that exhibits chaotic dynamics. To name a few, energy harvesters are more effective if they operate over a wider bandwidth and this can be possible by having a mass that is bistable. Similarly with a bistable structure driven in chaotic mode, a cryptographically secure random number generator could be implemented. Another application that we might delve into is a secure communications channel having a synchronised chaotic carrier; once again this could be generated with a bistable structure operating in the chaotic regime.
We are currently working in an EU ENIAC project called LAB4MEMS aimed at developing new production pilot lines related to MEMS production. In this project we are mainly involved with the modelling/design of MEMS piezo-actuated capacitors, resonators and compasses, as well as the effects of packaging on MEMS devices
When it comes to cryptographic applications and secure communication channels, the real challenge would be winning the trust of the end users and providing enough evidence that the system is secure from as many different attack vectors as possible. As for the energy harvesting application, it boils down to the power that the device could harvest, and specifically it would be designed to cater for some biomedical implants, the biggest challenge would be obtaining certification that the device is within the legal framework for such devices.
The area of MEMS is fast growing and a significant progress in terms of applications and increased integration is expected to take place. Since the department also has expertise in CMOS analogue and digital circuit design, we envisage eventually moving to complete system-on-chip designs. We also aim to entice local industry to set up design teams to work in this evolving area of expertise.
This article is based on the Letter: ‘The versatility provided by an electrostatic torsional microstructure as a consequence of its complex dynamics’ (new window).
A PDF version (new window) of this feature article is also available.
Browse or search all papers in the latest or past issues of Electronics Letters on the IET Digital Library.