Microfluidic modular heat sink with improved material characteristics towards thermal management of flexible electronics

Thermal management of the hotspots produced by the electronic chips is a significant issue for contemporary flexible electronic devices. Being elastic in nature, polydimethylsiloxane (PDMS)-based microfluidic devices can be used as flexible heat sinks. However, the subpar thermal conductivity of PDMS makes it inapt for practical implementation. To address this issue, a PDMS-graphene oxide (GO) nanocomposite-based microfluidic heat sink was proposed as an alternative option for flexible electronics. The thermal and material characteristics of the PDMS-GO nanocomposite were evaluated by incorporating different concentrations of GO nanoparticles. The incorporation of 5 % w/w GO nanoparticles enhanced the thermal conductivity and elasticity of the PDMS by a margin of 2.5-fold and 3-fold, respectively. Subsequently, microfluidic heat sinks of different PDMS-GO compositions were fabricated using a 3D printed scaffold-removal technique, and their efficacies were tested employing a microfluidic test rig and numerical simulations. Under similar testing conditions, PDMS-GO nanocomposite-based microfluidic heat sinks outperformed traditional PDMS-based heat sinks. This proof-of-concept study has the potential to offer a practical solution for the thermal management of flexible electronic devices, batteries, and on-demand microfluidic chip cooling.