Platform Support for 3D Electrical MEMS
Lead Research Organisation:
Imperial College London
Department Name: Electrical and Electronic Engineering
Abstract
This proposal is for renewal of the platform grant Platform Support in 3D Electrical MEMS , held by the Optical and Semiconductor Devices Group (OSDG), Imperial College London. The grant holders, Prof. Richard Syms, Dr. Andrew Holmes and Prof. Eric Yeatman, have built up a major research activity in micro-electro-mechanical systems (MEMS) over the last 14 years, and their group is the largest in this field in UK academia. One of the main areas of innovation for the group has been in methods for fabricating truly 3D structures based on planar semiconductor processing techniques. In recent years these techniques have been increasingly employed to develop electrical applications, including MRI/MRS detectors, ultra-low-power radio and micropower generation. The current platform grant (Jan 2004 - Dec 2007) has supported the establishment, development and unification of these themes, and thus to establish the group as an internationally recognised centre of excellence in electrical MEMS. It has also aided the creation of several important international collaborations. We have disseminated our work widely and extensively, and the flexibility of the platform funding has helped widen our dissemination activities beyond the conventional routes, such as coordinating the Electronic Systems theme within the International Review of UK Engineering Research 2004.Building on this success, we plan to extend and broaden our research in the current topic areas, and also to develop new activities in 3D MEMS, namely MEMS for minimally invasive surgery, wireless sensors, and electromagnetic bandgap materials. Platform support will also continue to provide continuity for our research staff, and to allow us to do exploratory work on new topics and ideas as they arise. Such exploratory work is of great assistance in identifying promising topics for larger scale projects, establishing feasibility, and initiating collaborative links. Research collaborations developed under the existing grant will be enhanced, and new links will be established with leading industrial and academic groups in the U.S. and in Europe. Dissemination and public engagement activities will also be enhanced, e.g. with contributions to the non-technical media on our work and its broader significance and context.
Organisations
Publications
Otter W
(2014)
100GHz ultra-high Q-factor photonic crystal resonators
in Sensors and Actuators A: Physical
Toh T
(2008)
A continuously rotating energy harvester with maximum power point tracking
in Journal of Micromechanics and Microengineering
He C
(2011)
A MEMS Self-Powered Sensor and RF Transmission Platform for WSN Nodes
in IEEE Sensors Journal
Malcolm A
(2011)
A miniature mass spectrometer for liquid chromatography applications.
in Rapid communications in mass spectrometry : RCM
Veladi H
(2008)
A single-sided process for differentially cooled electrothermal micro-actuators
in Journal of Micromechanics and Microengineering
Wright S
(2009)
Comparison of ion coupling strategies for a microengineered quadrupole mass filter.
in Journal of the American Society for Mass Spectrometry
Episkopou E
(2012)
Defining Material Parameters in Commercial EM Solvers for Arbitrary Metal-Based THz Structures
in IEEE Transactions on Terahertz Science and Technology
Herbertz K
(2010)
Electromagnetic bandgap filter with single-cell monolithic microwave integrated circuit-tuneable defect
in IET Microwaves, Antennas & Propagation
Mitcheson P
(2008)
Electrostatic Microgenerators
in Measurement and Control
Mitcheson P
(2008)
Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices
in Proceedings of the IEEE
| Description | We have pursued a wide-ranging research programme including activities on sensors, wireless sensing, energy harvesting, biomedical MEMS, RF MEMS, metamaterials and THz technology. Some highlights of the research are summarised below. (1) Sensors: A novel digital body motion sensor was developed based on a pattern embedded in the electrodes of a movable capacitor. Also, a method of functionalising chemical sensors was devised, based on microcontact printing using a self-aligned print 'engine'. (2) Wireless sensors and actuators: Work was carried out on ultra-low power radio for wireless sensors, leading to a short-range transmitter with exceptionally low power consumption (120 microWatts). An alternative approach was also explored where an energy harvester is coupled directly to an LC resonator, the inductor acting as a loop antenna. When excited, the harvester emits a signal proportional to the sensor output. Also, a new method based on ultrasonics was developed for delivering power to biomedical implants with actuation functions such as drug release. The system is purely mechanical and highly efficient. (3) Energy harvesters: An energy harvester was developed for human applications, where the excitation frequencies are low and random. Broadband performance was achieved by using magnets to attract beams to a rolling rod. These oscillate when released, allowing energy to be extracted. A shrouded wind turbine with a 2 cm rotor was also developed for energy harvesting in pipes. The harvester was integrated with low-power electronics and a radio to form a battery-less wireless sensor. (4) Biomedical MEMS: Methods of monitoring RF tissue fusion for bowel repair after tumour resection were investigated with St Mary's Hospital, Paddington. An optical method for monitoring absorption at 1.4 microns (which correlates strongly with tissue hydration and repair strength) was developed. Needle probes consisting of a plastic shaft containing an embedded RF coil for magnetic resonance detection were developed with CRUK. The detectors could operate up to 400 MHz frequency, allowing detection of cancer therapy drugs. Collaboration with the Imperial College spin-out Microsaic Systems led to advances in MEMS quadrupole mass spectrometers. A silicon-on-glass technology was demonstrated, reducing RF heating and extending the range to 1200 mass units. A pre-filter was also introduced, improving resolution at high mass. Combination with a MEMS vacuum interface and spray source forms a complete electrospray mass spectrometer, launched as a product in 2011. (5) RF MEMS: Together with Leeds University and Mitsubishi (Japan), micromachining was used to create microstrip transmission lines, RF-coupled cantilevers and a 3rd order filter with an insertion loss of 0.5 dB at 76.5 GHz. Tuning of coupled line resonators was also demonstrated. Together with Kasetsart University (Thailand), a 2-bit switchable delay was also demonstrated, based on two RF rotary switches and a delay line array. A high power latchable switch based on hydraulic microactuators was also developed. (6) Metamaterials: Two novel metamaterials were developed for RF transmission. The first is a stripline with a periodically defected ground plane which allows impedance matching to 50 Ohms. The second is an array of magnetically coupled L-C resonators that provides band-pass transmission but is intrinsically safe since it has no DC path. The materials have been mounted on catheters for use in internal MRI at St Mary's Hospital. (7) THz technology: A new terahertz technology was investigated in which the metal sidewalls of rectangular waveguides are replaced by photo-induced sidewalls within a high resistivity silicon substrate, allowing components to be reconfigured by changing the illumination. With double-sided illumination, an insertion loss of 1.3 dB/wavelength was achieved at 300 GHz. |
| Exploitation Route | Further collaborations have been developed with companies active in the area of RF MEMS, and with London area hospitals on RF detectors for medical imaging. |
| Sectors | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics,Energy |
| URL | http://www3.imperial.ac.uk/opticalandsemidev/microsystems/electrical |
| Description | A wide range of applications of miniaturisation technologies have been considered, including telecommunications and sensing, and general capabilities have been developed in the area of miniature RF and THz systems. The majority of the devices are based on MEMS or thin-film technology. In the former category fall RF connectors, switches and filters, and RF quadrupoles for miniature mass spectrometers; into the latter category fall RF receivers. Some devices have been exploited commercially (for example, RF quadrupoles, by the Imperial College spin-out company Microsaic Systems). Other devices have attracted interest from colleagues in Imperial College NHS Trust hospitals such as St Mary's Paddington and the Hammersmith hospital (for example, MR imaging endoscopes and catheter probes). A Centre for Terahertz Technology has been established at Imperial College, which is now considering further applications in the THz waveband such as secure communications and medical imaging. |
| First Year Of Impact | 2010 |
| Sector | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Healthcare |
| Impact Types | Economic |
| Description | AWE |
| Amount | £149,000 (GBP) |
| Funding ID | XXXx |
| Organisation | Atomic Weapons Establishment |
| Sector | Private |
| Country | United Kingdom |
| Start | 01/2010 |
| End | 12/2010 |
| Description | AWE |
| Amount | £149,000 (GBP) |
| Funding ID | XXXx |
| Organisation | Atomic Weapons Establishment |
| Sector | Private |
| Country | United Kingdom |
| Start | 01/2010 |
| End | 12/2010 |