Researchers at Concordia University have developed a 3D-printing method that uses focused sound waves to build microscale structures on soft polymers such as silicone. The technique, called proximal sound printing, produced features up to 10 times smaller than previous sound-based approaches while consuming less power and improving repeatability. Results were published in February 2026 in the Nature journal Microsystems & Nanoengineering.
The method works by directing focused ultrasound at a liquid polymer to trigger a chemical reaction precisely where printing is needed. The polymer solidifies only at the focal point. Unlike conventional micro-printing techniques that rely on heat or ultraviolet light, sound-based printing is compatible with materials commonly used in microfluidic devices, lab-on-a-chip systems, and soft electronics — materials that are difficult to pattern at small scales with existing tools.
Concordia’s team first demonstrated the concept in 2022 with a technique called direct sound printing. That earlier work showed ultrasound could cure polymers on demand, but resolution and consistency were limited. The new proximal method positions the sound source much closer to the printing surface. The shorter working distance tightens the focal point and gives the operator finer control over where solidification occurs.
The practical result is the ability to print complex microfluidic channels, flexible sensors, and multi-material structures in a single process. Shervin Foroughi, who completed his PhD at Concordia in 2025, and Muthukumaran Packirisamy, a professor in the Department of Mechanical, Industrial and Aerospace Engineering at Concordia’s Gina Cody School, co-authored the paper with Mohsen Habibi from the University of California at Davis.
The technique targets applications where small, precise, and flexible components matter most. Medical diagnostic devices, wearable sensors, and soft robotic parts all require manufacturing at scales where traditional methods either lack precision or demand expensive cleanroom setups. Proximal sound printing could shorten prototyping cycles for these components by offering a simpler fabrication path.
The study received funding through a Natural Sciences and Engineering Research Council Discovery grant. Whether the method can scale beyond laboratory conditions will depend on further testing with production-grade materials and higher throughput requirements.
Article & image Source: Concordia University
