Recently we had the chance to speak with Dr. Cindy Harnett about her current research with LARRI on the Kampers EPSCoR project, the NeXuS system and her work as Co-PI on the NSF-funded EFRI SCRAM project. We learned of her passion for the vast array of functional fibers and their potential for the future in the field of robotics, wearables and actuators. Dr. Harnett also shared with us a little insight into her latest grant and what she loves about LARRI.
We began our conversation with Dr. Harnett’s role in the Kampers project where she focuses on placing sensors and actuators into wearable devices. The project’s aim is to detect when things stretch, bend, twist, and if touched, detect not only where, but also by how much force.. To capture this massive amount of information in a practical way the wearables need to be small, flexible and durable. Dr. Harnett is excited about using soft sensors, optical fibers and their capacity to transfer large amounts of data almost instantly to accomplish her research goals. She says,” Think about all the wires inside C-3PO, they have to be plugged in somewhere. Instead of having 80 different patch cords to plug in,” she wants to, “cram all that information into one single optical connector.” The team has had some success with this by using optical signals to carry deformation data, creating code libraries for other users and designing a component that can be added without a whole lot of complexity to plug in.
Dr. Harnett started looking at fibers as a kind of overlooked material for 3D printing. Their flexibility lets you manufacture 2D fiber layers with automation, and stack, roll, and fold the layers into 3D shapes. She says, “There are so many materials available as fibers that you can’t get 3D printed yet.” In a perfect world various conductive fiber material would come on a spool, be shelf stable and you could get it by the yard. Dr. Harnett concentrates on producing new fiber materials and demonstrating applications with the versatile, high-speed methods fibers can offer. Fibers can resist heat, repel water and still transmit signals, so they are, “great for experimenting with in messy situations.”
The NeXuS system is, “The heart of LARRI.” Dr. Harnett is leading the charge on the Loom component of the NeXuS system. The Loom is used to create new fibers from strings, allowing NeXuS to develop versatile materials for dynamic structures in wearables. Positioned next to the Loom weaving station is a robotic arm designed to manipulate, assemble, cut and connect terminals to fibers in hopes of speeding up productivity and uniformity. Dr. Harnett concentrates on aligning fiber arrays with MEMS to clasp onto conductive or sensor fibers with 3-D printed mechanical grippers with computing elements. She says her goal is to, “Simplify the job to include some processing right there in the fiber structure and have organized data come out.”
Dr. Harnett is also the Electrical Engineer and Co-PI for the NSF-funded EFRI SCRAM (Soft Curved Reconfigurable Anisotropic Mechanisms) project. Dr. Nick Gravish (PI) of U.C. San Diego and Dr. Harnett along with other collaborators from Arizona and Oregon are in year two of their grant, working to make soft, flexible reconfigurable actuators from different material like fibers, textiles or films. As the EE on the team, Dr. Harnett leads the development on drivers for optical sensors and thermal actuators based on shape memory alloys.
Dr. Harnett’s lab has two papers on Absolute Length Sensors measuring the flight time of light in stretchable optical fibers. One was published in IEEE Sensors Letters in 2020 and the other is currently under review.
Dr. Harnett has been an associate professor of Electrical and Computer Engineering at UofL since 2006. She earned her B.S. in Physics at Harvey Mudd College and her Ph.D. in the Applied and Engineering Physics program at Cornell University.