Hydrogel-Based Pressure Sensor Offers Subtle, High-Sensitivity Wearable Health Monitoring
Having overcome previous problems with hydrogel systems, a team has released details of a new method for developing low-cost wearables.
A team of researchers working with the Terasaki Institute have developed a wearable, pressure-sensitive device claimed to be suitable for long-term monitoring of pulse rate, blood pressure, breathing rates, and even vocal cord vibrations — based on hydrogel technology.
Sensors which track pressure changes around the body are nothing new — as anyone who's had a blood pressure test will attest — but are typically bulky. The team's work, by contrast, turns the sensors into something more like a strip of adhesive tape — but in an elastic hydrogel format, after researchers were able to overcome issues with evaporation, weakness, and expensive production methods.
"The advancements we have achieved with our hydrogel sensors have enabled us to successfully overcome the challenges from previous efforts," claims Dr. Shiming Zhang. "This will enhance the use of pressure-sensitive devices for many possible medical applications, which may include not only the continuous monitoring of blood pressure, pulse and breathing rates but also measuring vocal cord vibration for the early detection of voice and swallowing problems."
"Wearable sensors are convenient and accessible tools for monitoring patient health, and this work facilitates their production," adds Terasaki Institute director and chief executive Dr. Ali Khademhosseini of the work. "It synergizes well with our Institute's Personalized Devices platform, which aims to develop smart devices for continuous monitoring in real time."
The prototype wearable sensor developed by the team is built around a gelatin-based hydrogel, which offers high skin compatibility, good elasticity, and is producible at a very low cost — and turns transparent when solidified, making it more subtle to use as a wearable biosensor. By moulding a grid pattern with pyramid-shaped projections, the team was also able to improve its sensitivity as a pressure sensor — proving it could measure pressure changes better than the current state-of-the-art.
The team's work has been published under closed-access terms in the journal Advanced Functional Materials.