There have been recent proposals to build terrestrial gravitational-wave detectors in the ~0.1 to 10 Hz frequency
range using torsion balances. Such detectors will be sensitive to a different class of long-lived sources compared
to LIGO, such as intermediate-mass black-hole binaries. The seminar will describe an early prototype for such a detector,
consisting of a torsion balance with an interferometric angle readout with a sensitivity of ~ picoradian/rt(Hz).
Experimental challenges and results will be discussed along with plans for near-term upgrades and projected sensitivities.