Smart wearable patch offers adaptive heat therapy for arthritis

The system integrates multiple components into a flexible, multilayered design: 

• Kirigami-serpentine structure for stretchability and flexibility 

• Au temperature sensor 

• PEDOT-based humidity sensor 

• Joule heater for heat generation 

• Bluetooth-enabled closed-loop control 

All elements are embedded in a polyimide film, designed to fit joints such as the knee and stay effective during movement. 

Dr. Mengxi Wu, co-corresponding author, explains: "Our goal was to make thermal therapy truly wearable – not just portable, but adaptive and intuitive." 

The patch continuously collects data from its sensors and adjusts the heating output in within one second, maintaining a precise target temperature of 45°C with less than 0.1°C fluctuation. Key benefits include: 

• Programmable heat cycles for on-demand use 

• Automatic activation in cold environments 

• moisture control to reduce joint stiffness 

• Improved blood perfusion, as confirmed through photoplethysmography (PPG) 

Tests demonstrated the patch’s effectiveness during walking, stretching, and running, and its durability across more than 1,000 usage cycles. 

Although designed for arthritis, the flexible medical patch has potential applications in other temperature-sensitive conditions, such as: 

• Circulatory disorders 

• Muscle injuries 

• Autoimmune diseases 

• Rehabilitation therapy 

MEDICA-tradefair.com; Source: Dalian University of Technology