Nano-thin speaker glued to the skin plays Paganini

Korean scientists have created a flexible thin speaker and microphone based on silver nanowires. They attached the speaker layer less than 100 nanometers thick to the skin to reproduce Niccolò Paganini’s La Campanella.

The nano-membrane works on the basis of thermo-acoustics and is capable of producing sound by vibrating the surrounding air via temperature changes. These temperature fluctuations are generated by running current through the grid of nanowires.

The researchers also developed a microphone based on the nanomembrane, in which the membrane is incorporated between elastic layers. The microphone can very precisely detect the vibration using the triboelectric effect that occurs when the diaphragm comes into contact with the surrounding elastic layers, Spectrum describes.

The membrane is made up of a grid of silver nanowires less than a hundred nanometers thick, which are incorporated in a polymer. The researchers at Korea’s Ulsan National Institute of Science and Technology recognize that there are still some obstacles before it can be used in commercial applications. For example, the performance of the speaker must be considerably improved, as well as the durability of the nanomaterial.

According to them, the speaker is primarily a proof-of-concept and the breakthrough lies in being able to make an ultra-thin, transparent and conductive material with good optical, electrical and mechanical properties. In the long term, they believe the material could be used for wearable sensors and applications in healthcare.

The research was published in Science Avances under the title Transparent and conductive nanomembranes with orthogonal silver nanowire arrays for skin-attachable loudspeakers and microphones.