Single and double traps Computer simulations of MultiLev showing the acoustic field and pressure and the relative phase differences of transducers when the two particles (blue dots) are held separately (right) and held together (left). (Courtesy: Phys. Rev. E 114 045409/CC BY 4.0)"> Single and double traps Computer simulations of MultiLev showing the acoustic field and pressure and the relative phase differences of transducers when the two particles (blue dots) are held separately (right) and held together (left). (Courtesy: Phys. Rev. E 114 045409/CC BY 4.0)

Using a specially designed setup to levitate particles with sound, researchers in the UK have revealed that the electrical charge built up through repeated collisions between two particles follows a clear, predictable pattern. Led by Tom O’Hara at the University of Bristol, the team found that although each collision transfers a seemingly random amount of charge, the overall build-up follows similar rules to a charging capacitor.…