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Projects: Projects for Investigator
Reference Number EP/V000624/1
Title Integrated levitated optomechanical gravimeter
Status Started
Energy Categories Fossil Fuels: Oil Gas and Coal(Oil and Gas, Other oil and gas) 5%;
Not Energy Related 90%;
Fossil Fuels: Oil Gas and Coal(CO2 Capture and Storage) 5%;
Research Types Equipment 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Physics) 50%;
ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering) 50%;
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Dr J Yan

Sch of Electronics and Computer Sc
University of Southampton
Award Type Standard
Funding Source EPSRC
Start Date 01 August 2021
End Date 31 July 2024
Duration 36 months
Total Grant Value £836,594
Industrial Sectors Electronics; Energy; Environment
Region South East
Programme NC : Engineering, NC : ICT, NC : Infrastructure
Investigators Principal Investigator Dr J Yan , Sch of Electronics and Computer Sc, University of Southampton (99.999%)
  Other Investigator Professor H Ulbricht , School of Physics and Astronom, University of Southampton (0.001%)
  Industrial Collaborator Project Contact , BP International Ltd (0.000%)
Project Contact , WMG Catapult (0.000%)
Project Contact , Groupstars (0.000%)
Project Contact , VIAVI Solutions (0.000%)
Project Contact , Wisen Innovation (0.000%)
Web Site
Abstract Current highly sensitive gravimeters, such as superconducting spheres, atom interferometers, and torsion pendulums, suffer from high manufacture and maintenance cost (up to 400k), bulky size (as large as 2.5m^3) and slow measurement speed (typically 1 hour).Here we propose an exciting innovation in quantifying gravity, based on the frequency measurement of the gravity-induced precession in an optically levitated fast-spinning particle. This novel levitated optomechanical systems (LOMS) gravimeter can be fabricated on a silicon wafer with wafer-level vacuum encapsulation, making its footprint as small as one mm^2. The small size device is mass-producible with a fabrication cost potentially less than 4k.The proposed research uses the analogy of the precession of the Earth, a slow and continuous change in the orientation of the Earth's rotational axis induced by the gravity of the sun, to develop the novel gravimeter. In December 2018, our research for the first time revealed that the precessional motion also appears in sophisticatedly designed LOMS and that optical scattering techniques can precisely measure the frequency of precession (U9). Our calculation predicts that levitated rotating particles of 10um diameter can achieve the sensitivity of 10^-9 g/sqrt(Hz) and a very fast-spinning particle (GHz reported in 2018 (x19)) can achieve 10^-11 g/sqrt(Hz) sensitivity, respectively.The novel gravimeter can also measure the acceleration due to the Einstein equivalence principle. Thanks to the ultra-high Quality-factor (7.7x10^11 demonstrated in 2017 (x3)) of the rotating particles, the novel sensor will have the potential to cover 11 orders of magnitude of acceleration measurement.Moreover, using the advanced silicon fabrication technique, we will be able to differentiate the centre-of-mass and the centre-of-optical-force of the levitated particle, in order to optimise the range of the gravity (or acceleration) induced torque, and correspondingly design the sensing range and sensitivity of the acceleration, e.g. 10^-6 m/s^2 to 10^5 m/s^2 to cover the seismic and mining health monitoring applications or 1 m/s^2 to 10^11 m/s^2 for fundamental physics research. The sensor only requires short integration times (1ns to 100s, depend on the precession frequency). Thus, it can complete the measurement very rapidly. This novel precession sensing principle can also be utilised to measure force, strain, charge and mass, with similar ultra-wide dynamic range and ultra-high sensitivity potentially.The innovative gravimeter (accelerometer) can be a powerful tool for investigating fundamental physics questions in gravitation, which are pressing and very hard to access experimentally due to the weakness of the gravitational interaction if compared to other interactions. The proposed research can also provide a platform for quantum manipulation of mesoscopic mechanical devices in the nano-scale regime and can serve as a testbed for theoretical predictions.Furthermore, our novel sensor can equipt the oil and gas industry with its applications in CO2-EOR and exploration. It can track temporal and spatial variations of the gravitational field and provide highly accurate information of mass redistribution below the surface. The prototype on-chip LOMS gravimeter has a small footprint so that it can be installed close to the drilling bit. Based on Newton's law of universal gravitation, the gravimeter has the potential to detect 1.5x10^7 kg mass redistribution above the ground, and 1.5x10^5 kg mass redistribution inside the wellbore. The sensitivity of the novel gravimeters installed inside wellbores can be four orders of magnitude better than that of the existing highly sensitive gravimeters.Our research also contributes to CSS, mineral exploration, structural safety monitoring for mining, earthquake warning, inertial navigation and geoscience, and can lead to significant cost savings in multiple industries.
Publications (none)
Final Report (none)
Added to Database 22/10/21