Nanomechanical resonators are vital to precision sensing and emerging quantum technologies, but their extraordinary sensitivity comes with an unexpected vulnerability.

A nanomechanical device can lose much of its ability to sustain vibrations without ever touching another object. Researchers at EPFL have discovered that placing insulating materials just a few hundred nanometers from these tiny structures can dramatically increase energy loss, reducing their mechanical quality factor by as much as tenfold.

The findings, published in Nature Physics by scientists in the group of Tobias J. Kippenberg, identify a previously underappreciated limitation for ultrahigh-precision sensors and quantum technologies. The source of the problem is an electrical interaction that allows energy to escape across an otherwise empty gap.