A novel heatsink for thermo-electric power harvesting of structural health monitoring systems

Recent research in energy harvesting is leading to the possibility of developing self-powered structural health monitoring (SHM) systems for aerospace applications. Particularly, temperature gradients originated at different locations of the aircraft can be converted into electric current by using thermoelectric generators (TEGs). TEGs are a suitable option for power harvesting since they (i) can be easily mounted on aircraft components, (ii) are lightweight, (iii) do not contain movable parts and (iv) provide high-energy conversion. TEGs are generally combined with thermal diffusion systems (heatsinks) to dissipate heat from a high temperature surface to the ambient air. The present study investigates the design, manufacturing and testing of a novel air-cooled heatsink used to increase temperature gradients on the surfaces of a commercial TEG element and, in turn, the power generation. In particular, a novel heatsink geometry and hybrid material configuration are analysed to enhance the heat spread in the power harvesting system in order to further improve the TEG performance. Numerical finite element simulations and experimental tests are carried out to assess the characteristics of the novel heatsink in combination with a commercial TEG device. Experimental results reveal that the proposed thermal diffusion system provides higher level of performance in comparison with traditional fin array heatsinks. Moreover, considering 100°C and 25°C as heat source and ambient temperature, respectively, the presented heatsink-TEG arrangement produces enough energy to power an ultrasound SHM system for aerospace applications (output power over 30 mW).