A group around Richard Middlemiss presented now a new kind of gravimeter based on conventional MEMS technology, which is used in evryday’s mobile phones, and presented their results in the world leading journal Nature.
The ability to detect tiny variations in the local gravitational acceleration is very important in, e.g. finding new hydrocarbon reserves as well as in understanding volcanic activity.
Yet precise gravimeter are bulky, heavy and very expensive.
The new gravimeter uses a 200 µm thick silicon chip, which has been oscillatingly suspended on springs. Changing now the gravitational acceleration the chip changes its position and thus the resonance frequency of the mechanical system changes. Furthermore, a LED illuminated the chip. While rotating, less light falls to the detector and together with the resonance frequency shift the system gains a very high accuracy in the measurement. (doi:10.1038/nature17397)