Autonomic Cooling of Composites Using Transpiration

Abstract

In nature, plants use transpiration to transport water against gravity from the soil to their leaves, powering the flow of nutrients throughout the plant. During transpiration, water evaporates from the leaves (i.e. porous network) and is replenished by the xylem (i.e. vascular channels) from the water stored in the soil (i.e. reservoir). In our synthetic system, autonomic cooling of a structural composite is accomplished using a leaf inspired vascularized coating. In response to an external heat load, evaporation occurs from pores in the coating to remove heat. The fluid is then replaced by capillary action from an externally located reservoir, allowing for continuous operation. Experiments demonstrate the cooling performance of the system, its ability to self-start and stop, and the ability to remotely locate the reservoir.