New Paper in Scientific Reports

Researchers at the Laboratoire Léon Brillouin (CEA-CNRS), Univ. Paris-Saclay have demonstrated that ordinary liquids can emit a modulated hot and cold thermal signal upon applied mechanical shear wave (Figure below). It tells that the mechanical energy is not dissipated but converted in local thermodynamic states. Prof. Laurence Noirez together with her student Eni Kume (ESR 5) thus identified the equivalent of the thermo-elasticity which was known in solids only.

These experimental advances are utmost important for liquid theories and microfluidics, and open the way to a new generation of energy-efficient temperature converters. View the article

By applying a low frequency shear mechanical stimulus (~ Hz), the liquid emits a modulated thermal signal synchronous with the stimulus. Real-time mapping of the temperature variation of the PPG-4000 confined in a 240 µm gap (gap view) excited by an oscillatory shear strain γ = γ0.sin(ω.t) with γ0 = 4,000% and ω = 0.5 rad/s (alumina substrate). Black dotted line is an eye guide for the applied strain.