Proximal sound 3D printing uses focused ultrasound waves to trigger chemical reactions that solidify liquid polymers like silicone

https://techxplore.com/news/2026-02-based-3d-method-enables-finer.html

"higher precision/ efficiency positioning sound source closer to printing surface... works with materials required for flexible electronics/ microfluidics... achieves complex, multi-material features up to 10X smaller using less power... much higher repeatability/ consistency... healthcare: faster medical diagnostic tool prototyping, lab-on-a-chip systems, wearables: advanced flexible sensors/ soft robotic components, environmental monitoring: highly sensitive microscale sensors for real-time data collection"