Design of redundant microvascular cooling networks for blockage tolerance

Microvascular networks can provide host materials with many functions including self-healing and active cooling. However, vascular networks are susceptible to blockage which can dramatically reduce their functional performance. A novel optimization scheme is presented to design networks that provide sufficient cooling capacity even when partially blocked. Microvascular polydimethylsiloxane (PDMS) panels subject to a 2000 W m⁻² applied heat flux and 28.2 mL min⁻¹ coolant flow rate are simulated using dimensionally reduced thermal and hydraulic models and an interface-enriched generalized finite element method (IGFEM). Channel networks are optimized to minimize panel temperature while the channels are either clear (the O₀ scheme), subject to the single worst-case blockage (O₁), or subject to two worst-case blockages (O₂). Designs are optimized with nodal degree (a measure of redundancy) ranging from 2 to 6. The results show that blockage tolerance is greatly enhanced for panels optimized while considering blockages and for panels with higher nodal degree. For example, the 6-degree O₁ design only has a temperature rise of 7 °C when a single channel is blocked, compared to a 35 °C rise for the 2-degree O₀ design. Thermography experiments on PDMS panels validate the IGFEM solver and the blockage tolerance of optimized panels.