A new innovative thermometer measures temperature with sound!

Measuring the temperature quickly and accurately has become, today, a fundamental task, thermometers can be of many types and each one has a different objective. Now, researchers from the University of Pittsburght and the University of Maryland have developed one such device that measures temperature using sound, a study they have called, “Detection of Acoustic Blackbody Radiation with an Optomechanical Antenna.”

When an object is heated, it is capable of not only changing color, as in the case of metal that turns red, but also of emitting acoustic energy, a weak sound that is difficult to perceive. Thus, the two researchers have used a nanomechanical resonator to detect this acoustic radiation in the objects, the thermometer has a zone composed of silicon nitrate which, over a window cut into a silicon substrate, transmits sound waves.

During the study, they deposited a drop of material on the silicon nitride and heated it with a laser, at which point the material began to emit acoustic energy, which travels through the apparatus and repeats patterns of vibrations in the membrane, which were detected by a second laser. The power of the heating laser varied, so the researchers found that the acoustic energy directly followed the temperature of the blackbody, and the vibration patterns were different depending on which body was being heated.

In conclusion, the researchers estimated that 99% of thermal movement comes from black bodies, thus showing significant immunity to “self-heating”, an effect that does affect conventional thermometers.

The researchers hope to build on this finding to create a compact and precise device that can be used outside of the laboratory. As they explained, this technique could be used to adopt improvements in applications ranging from metrology to quantum mechanics.