New Experimental Constraints on Non-Newtonian Forces below100μm

We have searched for large deviations from Newtonian gravity by means of a finite-frequency microcantilever-based experiment. Our data eliminate from consideration mechanisms of deviation that posit strengths $\sim {10}^4$ times Newtonian gravity at length scales of $20\mu \mathrm{m}$. This measurement is 3 orders of magnitude more sensitive than others that provide constraints at similar length scales.