Hygrally activated displacement inverter using a multiphysics multiscale topology optimization with considering evaporation

This study explores the application of concurrent multiscale topology optimization in the design of lightweight hygral-activated porous compliant mechanisms. The proposed approach utilizes two distinct representations of the design problem, namely macro and microscale domains, to achieve an optimized design. By implementing a concurrent multiscale topology optimization framework, the effective properties of the microscale, including elastic and hygral diffusivity tensors and the hygral expansion coefficient, are calculated and used as the hygro-elastic modeling effective properties of the macroscale. Furthermore, this study considers hygral transport in solids and hygral evaporation, thereby enabling simultaneous consideration of hygral transfer physics. A sensitivity analysis of the proposed concurrent optimization scheme was performed to address both macro and microstructure coupling, as well as hygro-elastic physics coupling. Numerical simulations were conducted for various single and multiple microstructure systems to investigate their performance. A study was also carried out to examine the impact of incorporating multiple microstructures into a single macro design domain on the macrostructure's dependency. The results showed that the use of multiple microstructures improved the design freedom and performance-to-weight ratio of the macrostructure.