  We propose a new approach to measuring persistent currents in normal metal
rings. By integrating micron-scale metal rings into sensitive micromechanical
cantilevers and using the cantilevers as torque magnetometers, it should be
possible to measure the rings' persistent currents with greater sensitivity
than the SQUID-based and microwave resonator-based detectors used in the past.
In addition, cantilever-based detectors may allow for measurements in a cleaner
electromagnetic environment. We have fabricated ultra sensitive cantilevers
with integrated rings and measured their mechanical properties. We present an
estimate of the persistent current sensitivity of these cantilever-based
detectors, focusing on the limits set by the cantilever's Brownian motion and
the shot noise in the laser interferometer that monitors the cantilever.
