New technology could allow real-time, wearable monitoring of skin and tissue stiffness

The research team has designed a simple, miniature electromechanical device for high-precision and real-time evaluations of deep tissue stiffness. Photo courtesy Dr. Yu Xinge's team

Researchers have developed a non-invasive sensor that can measure tissue stiffness in the skin, up to 8 mm deep. They hope this technology will be a valuable tool for aiding in medical diagnosis.

In a press release, the developers of the device note that electromechanical systems can provide useful clinical information through the measurement of tissue stiffness. However, many of the existing devices are large and require specialized training to use. Many of these devices can only evaluate stiffness at shallow depths.

Details of the research were published online in Nature Biomedical Engineering (May 27, 2021).

The newly developed device is built from a small electromagnetically driven vibrating actuator and a soft strain-sensing sheet. It can be adhered to the skin and then monitor in real-time the tensile stiffness of skin and other soft biological tissues at depths of approximately 1 to 8 mm, depending on the sensor designs.

A range of synthetic and biological materials, such as hydrogels, pigskin and human skin were used to test the device. The team also evaluated the device on the skin of humans who had a number of skin conditions, including psoriasis.

“The lesions exhibited higher stiffness than those of the nearby skin, primarily due to differences in skin elasticity and hydration. These simple measurements have potential clinical significance in rapidly identifying and targeting skin lesions, with capabilities that complement those of recently reported methods for sensing mechanical properties at tissue surface [typically micrometre-scale],” said the research team’s co-lead Dr. Yu Xinge, in the release. Dr. Yu is an assistant professor from City University of Hong Kong’s Department of Biomedical Engineering.

Dr. Yu pointed out that cancer tissue is typically stiffer or softer than normal tissue, and such differences can be used as a diagnostic biomarker for a range of skin conditions, like skin cancer or tumours under the skin.

The device has the potential to be used for the evaluation of physical skin properties under various conditions such as aging, hydration loss or associated dermatologic disorders, said Dr. Yu. “In the near future, we believe this technology will allow people to monitor their skin health status anytime with a simple wearable device.”