Resolving Thermal Accumulation and Rigid-Soft Interface Mismatch in Stretchable Electronics with Cubic Boron Nitride...

Area of Science:

• Materials Science
• Mechanical Engineering
• Robotics

Background:

• Effective thermal management is crucial for integrated stretchable electronic systems in soft robotics and wearable devices to prevent heat buildup.
• Existing systems face challenges in dissipating heat generated by functional components, potentially limiting performance and safety.

Purpose of the Study:

• To propose and demonstrate an island-bridge architecture with localized thermally conductive composite islands for enhanced heat dissipation in stretchable electronics.
• To improve the thermal safety and mechanical reliability of stretchable electronic systems for human-contact applications.

Main Methods:

• Incorporation of cubic boron nitride (c-BN) into selected regions of a soft substrate to create thermally conductive composite islands.
• Fabrication of an island-bridge architecture for stretchable electronic systems.
• Characterization of thermal conductivity, temperature reduction, and mechanical stretchability.

Main Results:

• Achieved in-plane and through-plane thermal conductivities of 2.327 and 2.596 Wm^-1K^-1, respectively, using c-BN composite islands.
• Reduced peak temperature by 12.8 °C compared to a substrate without composite islands.
• Increased stretchability from 70.41% to 122.67% by mitigating rigid-soft interfacial mismatch and stress concentration.

Conclusions:

• The proposed island-bridge design with localized composite islands effectively enhances heat dissipation and mechanical reliability in stretchable electronics.
• Demonstrated a stretchable computing platform operating below 40 °C, ensuring thermal safety for human-contact applications.
• The design offers a viable strategy for long-term stability in soft robotic end-effectors and wearable systems.