Direct sound printing is a potential game-changer in 3D printing, according to Concordia researchers

https://www.concordia.ca/news/stories/2022/05/31/direct-sound-printing-is-a-potential-game-changer-for-manufacturers-of-microdevices.html

"polymer used additive manufacturing polydimethylsiloxane (PDMS)... transducer generate ultrasonic field passes through shell and solidifies the targeted liquid resin and deposits it onto a platform or another previously solidified object. The transducer moves along a predetermined path, eventually creating the desired product pixel by pixel. The microstructure’s parameters can be manipulated by adjusting the duration of the ultrasound wave’s frequency and the viscosity of the material being used"