Wee-g: a wideband Micro-Electro-Mechanical-Sensor for applications in Gravity Surveying and Gravitational Wave Astronomy

This project will focus on analysing the data from an array of Wee-g MEMS gravimeters. Wee-g is highly novel and the world's first MEMS gravimeter (R.P. Middlemiss et al., Nature 531, 2016) which was able to show sufficient sensitivity and stability to monitor the Earth tides: elastic deformations in the Earth due to the tidal potential of the Moon and the Sun. Since then, the team have been working on commercialising the technology and developing a field prototype, engaging with industries in the areas of oil & mineral prospecting, environmental monitoring and defence & security. The device is fabricated in partnership with Glasgow spin-out Kelvin Nanotechnology (KNT), within the James Watt Nanofabrication Centre, and utilises an FPGA readout to monitor both the device and tilt/temperature environmental channels. This system is undergoing field trials in 2021, with the aim to deploy 20 units onto the side of Mt Etna in 2021/22, for the world's first gravity imaging array on a volcano.

Analysing data from arrays of gravimeters has never been done before, so our methodology will be to undertake side-side field trials with our industry partner Bridgeporth (http://www.bridgeporth.com/ ), where data from their single device can be compared to multiple MEMS "pixels". We will deploy multiple MEMS sensors over a region and optimise the array for spatial and time-lapse surveys, to image underlying gravity anomalies, take data at a higher rate to extract seismic background noise more efficiently, and applying wavelet analysis to notch out seismic noise. We will harness Institute for Gravitational research expertise in Bayesian inference & machine learning to identify and learn; instrumental drift via switching instrument location, temperature sensitivity, and sensitivity to external seismic noise, to optimise the data returned. A further innovative opportunity is installation of devices in the STFC Boulby facility and LIGO sites to study long term seismic and gravity changes