Avoiding heating interference and guided thermal conduction in stretchable devices using thermal conductive composite islands

The miniaturization and high integration of devices demand significant thermal management materials. Current technologies for the thermal management of electronics show some limitations in the case of multiple chip arrays. A device in multiple chip array is affected by heat from adjacent devices, along with thermal conductive composite. To address this problem, we present a nano composite of aligned boron nitride (BN) nanosheet islands with porous polydimethylsiloxane (PDMS) foam to have mechanical stability and non-thermal interference. The islands of tetrahedrally-structured BN in the composite have a high thermal conductivity of 1.219 W·m^-1·K^-1 in the through-plane direction (11.234 W·m^-1·K^-1 in the in-plane direction) with 16 wt.% loading of BN. On the other hand, porous PDMS foam has a low thermal conductivity of 0.0328 W·m^-1·K^-1 in the through-plane direction at 70% porosity. Heat pathways are then formed only in the structured BN islands of the composite. The porous PDMS foam can be applied as a thermal barrier between structured BN islands to inhibit thermal interference in multiple device arrays. Furthermore, this composite can maintain selective thermal dissipation performance with 70% tensile strain. Another beauty of the work is that it could have guided heat dissipation by assembling of multiple layers which have high vertical thermal conductive islands, while inhibiting thermal interference. The selective heat dissipating composite can be applied as a heatsink for multiple chip arrays electronics.