Fantastic phonons: Blocking sound, channeling heat with 'unprecedented precision'

Imagine living on a bustling city block, but free from the noise of car horns and people on the street. The emerging field of phononics could one day make this a reality.

The phonon, like the photon or electron, is a physical particle that travels like waves, representing mechanical vibration. Phonons transmit everyday sound and heat. Recent progress in phononics has led to the development of new ideas and devices that are using phononic properties to control sound and heat, according to a new review in Nature.

One application that has scientists buzzing is the possibility of controlling sound waves by designing and fabricating cloaking shells to guide acoustic waves around a certain object – an entire building, perhaps – so that whatever is inside the shell is invisible to the sound waves.

The future possibilities for phonons might also solve the biggest challenges in energy consumption and buildings today. Understanding and controlling the phononic properties of materials could lead to novel technologies to thermally insulate buildings, reduce environmental noise, transform waste heat into electricity and develop earthquake protection, all by developing new materials to manipulate sound and heat. These ideas are all possible in theory, but to make them a reality, phononics will have to inspire the same level of scientific innovation as electronics, and today that's not the case.