Development of a MEMS Gravimeter for Mineral Exploration using Measurement of Earth Density Variations, NRPU, HEC Rs 10.8 Millions)

Funding Agency: HEC
Scholarships available: 5 MS for Rs 20k and 1PhduptoRs 45k
Starting Date: February, 2022
Amount: Rs 22 Millions

Development of an ultra-low-g highly sensitive gravimeter in the applications of MEMS gravimetry and seismology e.g., mineral exploration, measurement of earth’s density variation, earthquake detection and observation, geophysical sensing, etc. The development of such a gravimeter will result in greater accuracy in the measurement of gravity and mineral exploration. This requires readily available, low cost, highly precise, and low cost inertial sensors. Among these inertial sensors, the advancements in the design and production of low frequency MEMS accelerometers is indispensable for earthquake monitoring and seismic surveying. Geometric Anti-spring (GAS) technology has been used for lowering the spring constants of accelerometers in macro scale for a while now. A similar principle can be used for MEMS gravimeters, for which the GAS typically consists of a set of curved, pre-stressed springs attached to the proof mass. The springs can be compressed or loaded passively with a force due to earth gravity, or actively with a dedicated actuation system. The compression of the springs effectively decreases the resonance frequency along the axis of the sensitivity of the mass-spring system, which significantly increases the sensitivity of the gravimeter. The negative stiffness property of other springs as curved beams has also been utilized in literature for the purpose of lowering the spring constant hand hence reducing the resonant frequency of the device