Future Manufacturing with Focused Ultrasound

Investigators at the Laboratory’s Center for Industrial and Medical Ultrasound (CIMU) have disrupted medical treatments by harnessing the power of acoustic energy delivered inside the human body. Now, a multidisciplinary team centered at CIMU is developing a manufacturing technique they call SonicBond based on well-known high-intensity focused ultrasound (HIFU) technology. It could change the way entire industries assemble the ubiquitous devices of modern life: tablets and smartphones, wearables and toys. 

Many of these devices are complex assemblies of mixed materials, electronics, and batteries bonded with thermal epoxies. These adhesives are cured by heat to create strong, durable bonds between materials. The team’s alternative to the traditional oven-curing process that predates our era of smart electronic devices, SonicBond, delivers acoustic energy to generate heat in a precise target zone, sparing heat-sensitive components such as lithium-ion batteries from exposure. HIFU has a unique combination of speed, precision, and adaptability, offering manufacturers an innovative tool that aligns with modern production demands.

CIMU Director Thomas Matula leads the team that includes Mechanical Engineer Cody Birkland, recent MBA graduate from the UW Foster School of Business Amy Swanson, and Mike Pinch, a Seattle-based mechanical product design engineer. Early experiments with thermal camera imaging show that ultrasound energy deposition is both controlled and precise, that appropriate epoxy curing temperatures of 100°C are generated only 2 to 3 mm distant from safe, lower temperatures. They have also shown that the HIFU heating process is self-limiting and that a steady-state curing temperature can be maintained for over 10 minutes. Further studies demonstrate that a greater mass of epoxy can be cured over the same amount of time by increasing the ultrasound power. Matula points to an early achievement: HIFU bonded polycarbonate and composites have shear strengths similar to those same materials bonded by traditional oven curing.

Birkland’s engineering is essential to driving the project further. He has designed a pulse-echo apparatus to measure acoustic attenuation of the HIFU beam through various coupling materials, including plastics, glass, and metals, as well as to measure the acoustic scattering across boundaries between materials. The team’s HIFU apparatus has been integrated into a computer-controlled motor system designed to (re)position the transducers over complex assemblies. And they have shown that HIFU parameters – frequency, duty cycle, and pulse length – can be tuned to optimize energy delivery to different materials.

To bridge the gap between university research and industrial application, the team plans to build and test a programmable HIFU lab prototype as a demonstrator to potential sponsors and commercial partners. The SonicBond idea makes sense upon initial presentation, but the prototype will be critical to give hands-on demonstrations of HIFU’s ability to target bond areas, minimize thermal damage, and be effective across a range of adhesives and materials. Swanson says that those most interested in the technology are engineers like Pinch, who are looking for an alternative to oven curing for complex stack-ups that contain batteries and magnets. "They are excited that HIFU can go through curved surfaces and opaque materials with targeted spatial control."

APL-UW Team Members

Research Sponsors