The experiment Thomas Penny, Yu-Han Tseng and Cecily Lowe observe nanoparticle collisions at Yale University. (Courtesy: Yale Wright Lab)"> The experiment Thomas Penny, Yu-Han Tseng and Cecily Lowe observe nanoparticle collisions at Yale University. (Courtesy: Yale Wright Lab)

A silica nanoparticle levitated in an optical trap could be used as a tiny pressure sensor that detects collisions with individual atoms and molecules – according to researchers in the US. Their proof-of-principle demonstration originated in the team’s work in developing novel neutrino and dark-matter detectors. It could lead to the development of a background pressure sensor to work alongside other optomechanical sensors.

In recent years, physicists have proposed that hypothetical particles such as dark matter could be detected when they occasionally scatter from nanometre-sized objects held in optical traps.…