Nanofabricated torsion-pendulum suspensions for tabletop gravity experiments
Phys. Rev. Applied 25, 054033 – Published 13 May, 2026
DOI: https://doi.org/10.1103/mnrd-3bm2
Abstract
Measurement of mutual gravitation on laboratory scales is an outstanding challenge and a prerequisite to probing theories of quantum gravity. A leading technology in tabletop gravity experiments is the torsion balance, with limitations due to thermal decoherence. Recent demonstrations of lithographically defined suspensions in thin-film silicon nitride with macroscale test masses suggest a path forward, as torsion pendulums dominated by gravitational stiffness may achieve higher mechanical quality factors through dilution of material losses. Here, we demonstrate a torsion fiber supporting 87 g and forming a Cavendish-style torsion pendulum with tungsten test masses that is the largest thin-film silicon-nitride-based oscillator to date. Torsion pendulums with thin-film nanofabricated suspensions provide a test bed for near-term tabletop experiments probing classical and quantum gravitational interaction between oscillators.
