Hongyi Shen, left, a graduate student in the School of Mechanical and Materials Engineering, and Professor Kaiyan Qiu helped lead a project that developed an electronic skin that can detect pressure and temperature.
Photo Credit: Sravanthi Yalamanchili/WSU
Scientific Frontline: Extended "At a Glance" Summary: Electronic Skin for Prosthetics
The Core Concept: Researchers have developed a customizable electronic skin for prosthetics that senses temperature and pressure at ten times the resolution of current commercial glove sensors, aiming to provide human-like tactile feedback.
Key Distinction/Mechanism: Unlike current e-skins that suffer from low sensing resolution, poor fit, high cost, and real-time data processing issues, this system uses a "scan-model-print" manufacturing method. This method maps sensor modules—thin-layered, Lego-like sandwiches containing temperature and pressure sensors—to the exact geometry of a limb, ensuring seamless coverage and high-density sensing over freeform regions.
Major Frameworks/Components:
- Multimodal Sensing Modules: Thin-layered sensor sandwiches that capture both temperature and pressure data.
- Scan-Model-Print Manufacturing: A technique involving 3D printing and laser cutting to personalize fabrication based on the exact geometry of the prosthetic.
- Modular Assembly: Sensor elements snap together without the need for adhesives.
Branch of Science: Materials Science, Mechanical Engineering, and Biomedical Engineering.
Future Application: The research lays the groundwork for full bionic skin capable of both sensing and haptic stimulation. Future developments include creating an actuator to convert these sensing signals into nerve stimulations, allowing amputees to physically "feel" what they touch.
Why It Matters: This approach lowers the cost and complexity of producing medical-grade e-skins, making advanced, high-resolution tactile feedback a viable option for widespread clinical use, which could significantly improve the daily functioning and quality of life for amputees.
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| A robotic hand fitted with 3D-printed sensor module developed by the research team. Photo Credit: Sravanthi Yalamanchili/WSU |
An electronic skin with a sensing system that can detect pressure and temperature could someday be used to help amputees gain feeling in their prosthetics.
The system, developed by Washington State University researchers and detailed in a study published in the journal Cell Reports Physical Science, can sense at a scale ten times finer than current commercial glove sensors.
“This approach democratizes the production of medical-grade e-skins, making advanced tactile feedback viable for widespread clinical adoption,” said Hongyi Shen, a graduate student in the School of Mechanical and Materials Engineering and the first author of the paper. “This work lays a crucial foundation for a full bionic skin with both sensing and haptic stimulation functions on prosthetics.”
Haptic stimulation replicates the sense of touch. Providing even partial sensation for amputees could greatly improve their ability to perform tasks. While electronic skins are currently available, they are expensive and have low sensing resolution. They also often do not fit well and cover only small regions. In fact, the more e-skins are customized to a specific shape, the worse they perform in their sensing ability. Furthermore, the large amount of data generated by the sensing arrays means that they do not work well in real time.
“Often these devices are forced to compromise between comfort and mechanical reliability,” said Shen.
The WSU researchers developed a customizable sensing system for prosthetics that conforms to the freeform shapes of limbs and better mimics real human skin in its sensing abilities. The sensor modules they created are thin-layered sandwiches that incorporate temperature and pressure sensors. These elements allow for human-like tactile sensing, enabling the reliable identification of surface textures and material properties.
The researchers used a “scan-model-print” manufacturing method that allows for high-density sensing alongside personalized 3D fabrication.
“The scanner basically scans the prosthetic and then, based on the geometry, we map our sensors as a multimodal sensing system with that geometry,” said Kaiyan Qiu, the Berry Family Assistant Professor in the School of Mechanical and Materials Engineering and a corresponding author of the paper. “This enables our sensing system to have seamless coverage over the freeform region on the prosthetics.”
The sensors are accurate and reliable, capable of measuring both pressure and temperature at a high density across flat or curved surfaces. Rather than requiring adhesives, the sensor modules snap together like Legos.
“Our main manufacturing method using 3D printing and laser cutting is relatively simple, so it could be relatively low-cost and convenient,” said Qiu.
The project was partially supported by WSU’s National Science Foundation Research Traineeship in Next-Generation Robotics (NRT-LEAD), led by Prashanta Dutta, the Richard Schneider Jr. Professor and director of the School of Mechanical and Materials Engineering. Dutta is also a corresponding author of the paper. Additional support was provided by Qiu’s WSU startup and Cougar Cage funds.
The researchers have submitted an invention disclosure for a provisional patent with the WSU Office of Research Innovation and Entrepreneurship team. They are also working on an actuator that will eventually convert the sensing signals of the e-skin to let amputees know what they are touching. This would entail converting the sensing signals into the stimulation and signaling of nearby nerves.
Shen, an NRT-LEAD trainee, said he has had a longtime interest in helping people in rehabilitation settings and has a background in sensor technology and 3D printing.
“By doing this, I combined my interests,” he said. “I think what we are doing in this project is really someday going to help amputees make their lives easier with our device.”
Published in journal: Cell Reports Physical Science
Authors: Hongyi Shen, Nikolai Bogdev, Yusen Zhang, Shanshan Yao, Prashanta Dutta, and Kaiyan Qiu
Source/Credit: Washington State University | Tina Hilding
Edited by: Scientific Frontline
Reference Number: ms082026_01
