Weiyue Xin, a Ph.D. student in the Chemical Engineering Department, is the lead author of a paper recently published in Science Advances explaining how a UMass Amherst research team has discovered how to use elasticity to control the positions of solid micro-plates on curved 2D fluids. “Our research has applications in nanotechnology and other spheres where it’s desirable to have sophisticated, flexible devices that can respond to their environment,” said Xin. See ScienceDaily, Science Codex, and News Office release.
One real-world application of the team’s research includes flexible, ultrathin, and reconfigurable, wearable electronics.
This research is led by Xin’s advisor, Professor Maria Santore, with large contributions from other team members, including Professor Gregory Grason and Senior Research Fellow Hao Wu, all from polymer science and engineering.
As the UMass News Office release said, “A team of…researchers at the University of Massachusetts Amherst has demonstrated for the first time that the positions of tiny, flat, solid objects integrated in nanometrically thin membranes – resembling those of biological cells – can be controlled by mechanically varying the elastic forces in the membrane itself.”
According to the News Office release, “This research milestone is a significant step toward the goal of creating ultrathin flexible materials that self-organize and respond immediately to mechanical force.”
As the team’s Science Advances abstract explained, “We demonstrate how manipulating curvature in an elastic fluid lamella enables the reversible relative positioning of flat, rigid, plate-like micrometer-scale inclusions, with spacings from about a micrometer to tens of micrometers.”
In an experimental model comprising giant unilamellar vesicles containing solid domain pairs coexisting in a fluid membrane, the researchers adjusted vesicle inflation to manipulate membrane curvature and mapped the interdomain separation.
“A two-dimensional model of the pair potential predicts the salient experimental observations and reveals both attractions and repulsions,” said the team, “producing a potential minimum entirely a result of the solid domain rigidity and bending energy in the fluid membrane.”
The researchers said the impact of vesicle inflation on domain separation in vesicles containing two solid domains was qualitatively consistent with observations in vesicles containing many domains. The behavior differs qualitatively from the pure repulsions between fluid membrane domains or interactions between nanoscopic inclusions whose repulsive or attractive character is not switchable.
The research was supported by a grant from the U.S. Department of Energy. Additionally, Xin received partial support from a National Institutes of Health Trainee Fellowship. (May 2021)