NCSU in the process of developing wearable sensors
Posted February 4, 2015
Updated February 6, 2015
Raleigh, N.C. — Doctors can learn a lot about a person's health with tools to monitor the heart or muscle activity, however that information is limited because the tools are only used in the doctor's office, for a short period of time.
Engineers at North Carolina State University are in the process of developing microscopic, silver nanowires that will record this information over the period of a day, or longer.
Dr. Yong Zhu, an associate professor of mechanical and aerospace engineering at NCSU, said the nanowires are very conductive, meaning they can transmit electric signals from the surface of the skin to data recorders.
Zhu is part of a team using the nanowire technology for long-term health monitoring.
Conventional heart monitors use metallic, wet sensors that include a layer of gel to contact the skin, but over time they begin to fail.
"It's going to dry causing signal degradation and also it leads to skin irritation," Zhu said.
In a study published in the Royal Society of Chemistry, the NCSU team demonstrated that their wearable, dry sensors are as accurate as the gel based type used in hospitals or doctors' offices.
"I think in the medical community, we're seeing monitoring of data so we can do a better job of diagnosing and that means wearing electronics to collect the data," said Dr. Larry Silverberg, associate head of mechanical and aerospace engineering.
The sensors are designed to fit the skin and them move with the skin. One measures the strength of different joints and a coiled design is used for pressure sensors, like on pads attached to the bottom of the foot.
"It has to be flexible, stretchable, complaint, and soft," Zhu said.
Heart patients with intermittent heart issues and amputees could benefit from the nanowire technology. These types of sensors can be used to measure pressure points to help with fitting new prosthetics. It's also possible that these type of sensors may be used to assist robotic devices - where an amputee can use muscle activity in their upper arm to stimulate movement in a prosthetic hand.
The work was supported by the National Science Foundation through the ASSIST Engineering Research Center at NC State.