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Details of Grant 

EPSRC Reference: EP/C015045/1
Title: Development of a Dynamic Micro Analysis Raman Spectroscopy (DyMARS) System for characterisation of MEMS and NEMS
Principal Investigator: Hedley, Dr J
Other Investigators:
Arce-Garcia, Dr I Gallacher, Dr BJ
Researcher Co-Investigators:
Project Partners:
National Physical Laboratory QinetiQ
Department: Mechanical and Systems Engineering
Organisation: Newcastle University
Scheme: First Grant Scheme Pre-FEC
Starts: 01 August 2005 Ends: 30 April 2008 Value (£): 114,992
EPSRC Research Topic Classifications:
Instrumentation Eng. & Dev. Microsystems
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:  
Summary on Grant Application Form
The aim of this project is to construct the first dynamic stress measurement and analysis (DyMARS) system. This will perform high spatial, time resolved stress characterisation measurements on micro/nano-electromechanical systems (MEMS/NEMS) using Raman microscopy.Very little is known on the reliability of MEMS in the 'real' world. Devices are currently characterised using such techniques as profilometry, vibrometry (which measure the displacements and velocities of devices) and Raman spectroscopy (which measures the stresses of a static sample). However these techniques do not address the issues of dynamic stresses during the operation of such devices which ultimately lead to device failure. Although the final cost of MEMS/NEMS is inexpensive and therefore cheap to replace, costs incurred during development times are considerable. Additionally replacement of some devices, such as human implanted devices, is potentially hazardous. It is therefore essential to perform characterisation of MEMS/NEMS under their operational conditions to reduce development time and reduce risk of failure on critical systems.This project will construct a Raman microscopy system capable of time resolved measurements. The basic principle is to strobe the illumination source of the Raman system in synchronisation with the motion of the MEMS device. The spectrum of the emitted Raman signal gives a direct measure of the stress in the device at a particular instance in its motion. By building up a succession of Raman images at differing phases in the MEMS motion, a time history of the stresses in the MEMS device is mapped thereby identifying areas of high stress and potential failure.Additionally, this system will be unique in that it will be the only truly 3-dimensional characterisation metrology for MEMS. Current 3-dimensional characterisation techniques are severely limited as they rely on tracking the edge features of MEMS leading to an overall 'averaged' value for the motion. In contrast, this system will map in detail the motion of each part of the device.Two issues must be addressed for the system. Firstly the accuracy of identifying features in the Raman signal directly gives the resolution to which the stress contours can be measured. Secondly the speed of strobing of the illumination source limits the temporal resolution (and ultimately the operational speed at which a device can be characterised). The speed of illumination of the sample has an adverse effect on the stress measurement resolution of the system therefore the stress resolution/timing criteria must be optimised. These have been identified as 50 MPa and 10 MHz for this system (see 'Case for Support' for more details).Test samples will be fabricated to assist system development and determine system performance. DyMARS will then be used to characterise industrial and academic samples collected during the course of the project thereby aiding in the samples' commercial development and publicising the value of the DyMARS system.
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Organisation Website: http://www.ncl.ac.uk