  Measuring gravitational interactions on sub-100-$\mu$m 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$\,\mu$g) to allow close approach. Considering an experiment combining a
40$\,\mu$g torsion resonator with a source mass of comparable size
(130$\,\mu$g) at separations down to 25$\,\mu$m, and including limits from
thermomechanical noise and systematic uncertainty, we predict these devices can
set novel constraints on Yukawa interactions within the 1-100$\,\mu$m range.
