Medical micropumps that utilize Magnetic Shape Memory (MSM) alloys are small, powerful alternatives to conventional pumps because of their unique pumping mechanism. This mechanism, the transfer of fluid through the emulation of esophageal contractions, is enabled by the magneto-mechanical properties of a shape memory alloy and a sealant material. Because the adhesion between the sealant and the alloy determines the performance of the pump and because the nature of this interface is not well characterized, an understanding of sealant-alloy interactions represents a fundamental component of engineering better solid state micropumps in particular, and metal-polymer interfaces in general. In this work we develop computational modeling techniques for investigating how the properties of sealant materials determine their adhesive properties with alloys. In particular, we develop a molecular model of the sealant material polydimethylsiloxane (PDMS) and parameterize its interactions with Ni-Mn-Ga alloy surfaces for use in molecular dynamics simulations. We perform equilibrium molecular dynamics simulations of the PDMS/Ni-Mn-Ga interface to iteratively improve the reliability, numerical stability, and accuracy of the models and associated data workflows. In sum, we develop a model combining OPLS-UA and UFF force fields for simulating PDMS/Ni-Mn-Ga interfaces and demonstrate its promise for informing the design of more reliable MSM micropumps.
5:00 PM–7:00 PM Apr 23, 2019 (US - Arizona)
PCC North, 300 Level, Exhibit Hall C-E