BIOINSPIRED ENGINEERING FOR THERMAL MANAGEMENT
by Mohammed Ababneh, R&D Engineer
For decades science has looked for answers to tough problems from the ultimate design expert – nature itself. For the past 3.6 billion years, nature has designed creatures of flight, camouflage, and through constant adaptation developed solutions for resistance to the elements, and survival at large just to name a few. Human design, inspired by nature, has existed over more than 2000 years, tracing back to man’s development of kites – the most basic interpretation of aviation.
The approach remains equally valuable today and is now becoming more focused on the micro level. For example, the microscopic structure of a reptile’s skin can inspire today’s textile engineers to develop moisture-resistant yet breathable materials that provides comfort in harsh environments. Harvard’s Wyss Institute focuses exclusively on “using biological design principles to develop new engineering innovations that will transform medicine and create a more sustainable world.” Along with many innovative engineering companies, Advanced Cooling Technologies benefits from considering bio-inspired concepts to help develop our thermal management solutions.
Bioinspired engineering plays a key role in developing advanced thermal management solutions by offering insight into solving difficult thermal challenges. For example, one growing challenge is effectively dissipating highly concentrated heat sources, such as in lasers. For these high heat flux applications, novel multiscale wick structures are now being utilized in passive heat spreading devices such as Vapor Chambers. In vapor chambers using these advanced wick structures, the dominant liquid feed paths, which provide the cooling medium, are intermixed but independent from the vapor ventilation paths which carries the heat away. These devices have demonstrated the ability to passively transfer kW levels of heat! This multiscale wick structure is inspired by biological systems found in – believe it or not – the human lung.
The novel wick’s superhydrophobic surfaces and textured hydrophobic surfaces, like those found in the lungs, have a great potential to improve condensation heat transfer. They also have the potential that could largely lead to efficient condensers in power generation and desalination, decreased moisture‐induced efficiency losses in steam turbines, and high‐performance heat pipes for electronics cooling applications. The thermal performance and flexibility could be attributed to the strong capillary pumping from the bioinspired superhydrophilic wicking structure and the flexible polyurethane polymer connector design.
Observing the elegance of design in large- and small-scale aspects of nature, from the flight of the condor, to the microscopic texture of an organ lining, proves to be a significant trend that admittedly is more imitation than innovation!
More details about how bioinspired engineering plays a key role in thermal management could be found at: “Chapter 2: The Engineering History of Thermal Materials” Ababneh, Mohammed T.; Book chapter in “Bioinspired Engineering of Thermal Materials” Editor: Deng, Tao; Wiley & Sons, 2018.