Microscale torsion resonators for short-range gravity experiments

Measuring gravitational interactions on sub-100-μm length scales offers a window into physics beyond the Standard Model. However, short-range gravity experiments are limited by the ability to position sufficiently massive objects to within small separation distances. Here we propose mass-loaded silicon nitride ribbons as a platform for testing the gravitational inverse square law at separations currently inaccessible with traditional torsion balances. These microscale torsion resonators benefit from low thermal noise due to strain-induced dissipation dilution while maintaining compact size (<100 μg) to allow close approach. Considering an experiment combining a 40 μg torsion resonator with a source mass of comparable size (130 μg) at separations down to 25 μm, and including limits from thermomechanical noise and systematic uncertainty, we predict these devices can set novel constraints on Yukawa interactions within the 1-100 μm range.