A researcher in the University of Hawaiʻi at Mānoa’s College of Engineering has developed a new method to improve the bonding strength of silicone-based materials, a breakthrough that could enhance the durability and performance of soft biomedical devices, wearable technology and soft robots. These materials are used in things such as artificial muscles, flexible medical implants and fitness trackers—devices that need to bend, stretch and move with the human body without falling apart over time.
Silicone elastomers (rubbery, gel-like materials made from silicone) are widely used in soft devices because they are flexible, chemically stable, and compatible with human tissue. However, a key challenge in their use has been controlling how well layers or components stick together during manufacturing, particularly when curing temperatures and durations vary.
In a new Science Advances study, published July 16, lead author and UH Mānoa Department of Mechanical Engineering Assistant Professor Te Faye Yap, and her co-authors, developed a new framework to predict how well silicone materials will stick together by looking at how long and how hot they’re cured. Bonding too late results in a weak connection because the materials don’t have enough chemical interaction to hold together well, while bonding at the right time creates stronger, more durable joints. This method helps identify when a material will fail by peeling or breaking, allowing manufacturers to adjust curing and bonding processes to reduce the risk of devices coming apart.
Yap worked with co-authors at Rice University and Tulane University while she was a PhD student at Rice.
“Strong, consistent bonding is crucial to prevent leaks and device failure,” said Yap. “This framework expands the design and fabrication toolkit for silicone elastomeric devices—an advancement that aligns with the College of Engineering’s vision for on-island advanced manufacturing and innovation in Hawaiʻi.”
Smarter design for silicone technology
Using this new method, the team built soft robotic parts that curved 50% more and 3D-printed pieces that stuck together more than twice as well as usual. The model worked well even when curing temperatures were changed to speed up production or enable printing.
The research offers helpful guidance for building silicone devices using both molding and 3D printing. Overall, the study provides a simple and generalizable way to make soft devices stronger and more reliable, and has the potential to help shape future advances in flexible electronics and 3D-printed technology.
