Enhancing the efficiency of Electronic Cooling Devices by Bio-coatings

Boiling is considered as one of the effective cooling methods in electronics devices because of its high heat removal capability. One of the promising techniques for boiling heat transfer enhancement is surface modification. Here, we propose a novel method for surface enhancement via crenarchaeon Sulfolobus Solfataricus P2 bio-coating. Unlike the available surface modification techniques, which require expensive microfabrication devices (physical modifications) and have damaging impact on the environment (chemical modifications), the proposed coating is cheap, scalable and most importantly is biocompatible with no environmental toxicity. Crenarchaeon was cultured in a bath using a magnetic stirrer (Fig. 1). A kind of polymer, polyelaysine, is mixed with the crenarchaeon to increase the adhesion between silicon surface and crenarchaeon. Flow boiling experiments were performed in a high aspect ratio microchannel with 5x1.5x0.5 mm3 dimensions. Experiments were performed under atmospheric pressures, where distilled water was used as the working fluid. To examine the effect of coating, flow boiling tests were performed at mass fluxes ranging from 50 to 150 kg/m2s on surfaces with two different thicknesses. A bare silicon surface was tested as reference. Sample characterization has been done with SEM and AFM before and after the experiments. High speed camera was employed for analyzing the results in the flow boiling set-up. The obtained results indicated that the coated layer creates a porous structure with numerous pores, acting as nucleation sites during boiling and delay the critical heat flux (CHF) condition (Fig. 2). This study clearly represents the potential of surfaces with bio-coatings to obtain substantial energy saving and efficiency in electronics cooling devices.