A Skin Tension Controller for Chronic Skin Wound Enabled by Flexible Strain Gauges

Noninvasively applying mechanical loads on edges of the chronic skin wound is confirmed as an effective approach for accelerating wound chronic healing and reducing scarring. However, less effort has been put into measuring and controlling the magnitude of mechanical load for wound closure in real time. This study proposes a skin tension controller, which is able to provide and monitor the magnitude of the mechanical load applied for chronic wound closure. A flexible strain gauge is designed and fabricated to measure the magnitude of the mechanical load, which is applied by a miniaturized linear stepper motor module housed in a 3-D-printed platform. The gauge's electromechanical behavior is characterized on a homemade platform, and the results show that the gauge's performance is linear with the applied mechanical force within the 0–9 N range. In addition, the gauge successfully measures the magnitude of the skin tension on a simulated human skin model. The results indicate that the magnitude of the skin tension and the displacement of the linear stepper motor module exhibit a linear relationship, which confirms that the magnitude of the tension can be controlled linearly by adjusting the displacement.