A research team led by Xueju “Sophie” Wang at the University of Connecticut has developed a new approach to manipulating liquids using soft, magnetically reconfigurable ribbons. The work, carried out with collaborators at the University of Edinburgh and Syracuse University, presents a material system that can change shape on demand and then hold that shape without power. For microfluidics and other fluid-handling technologies, this introduces a controllable element that is both simple in structure and efficient in operation.
Wang, Z., Alkuino, G., Avis, S. J., Li, Y., Zhang, X., Zhang, Y., Li, S., Kusumaatmaja, H., Zhang, T., & Wang, X. (2025). Magnetically reconfigurable multistable ribbon arrays for liquid manipulation. Device, 100986. https://doi.org/10.1016/j.device.2025.100986
The core of the concept is a thin ribbon made from polydimethylsiloxane (PDMS) embedded with magnetic particles. When the material is prepared under compressive strain, each ribbon naturally buckles into one of three stable geometries. A brief magnetic pulse is enough to push the ribbon from one configuration to another, and once the actuation stops, the ribbon stays where it is. Because the shape persists without a continuous field, the researchers describe the behavior as a form of mechanical memory. This stability opens the door to using these ribbons as switches, valves or gates within small-scale fluid systems.
In one demonstration, the group embedded a single ribbon inside a two-dimensional microfluidic junction. By switching the ribbon between its stable shapes, the path of the liquid could be redirected to different outlets. The reconfiguration did not require pumps or moving parts, and after the magnetic field was removed the system remained in the selected state. For portable devices, or any system where power usage must be minimized, a passive element that can retain its setting offers clear practical benefits.
The researchers then explored how coordinated arrays of these ribbons could support more complex tasks. By arranging multiple ribbons into a small matrix and changing individual ribbons independently, the team was able to adjust the surface profile in a controlled and localized way. This, in turn, influenced how droplets behaved when placed on the surface. In array tests, the team positioned and guided droplets by selectively switching ribbon states, demonstrating that droplets could be held in place, released or routed along predetermined paths. Although the arrays were modest in size, the results suggest that larger grids could one day enable highly programmable, pixel-like fluid handling for lab-on-chip platforms.
Alongside the physical experiments, researchers at Edinburgh and Syracuse developed simulation frameworks to study how droplet forces interact with the changing geometry of the ribbons. These mesoscale models combine surface-tension physics with electrocapillary effects, giving designers a way to predict how different configurations will influence droplet motion. The models also provide guidance for scaling the arrays and refining the layout of future devices.
Because the ribbons require no power to hold their configuration, they offer a different design philosophy compared to traditional microfluidic systems. Many existing devices rely on continuous external fields or on mechanical components that increase complexity. The soft ribbons, by contrast, encode their state directly in the material shape, allowing a level of reconfigurability without the overhead of active control. This makes them particularly attractive for portable diagnostics, environmental sensing and compact laboratory systems where simplicity and low energy consumption are essential.
There are still engineering challenges to address. Larger arrays must remain reliable over repeated switching cycles, and the long-term stability of the magnetic material under routine use needs to be understood. Integrating these ribbon arrays with reservoirs, sensors and other microfluidic components will also require thoughtful design. Still, the early demonstrations highlight a platform with potential across several areas of materials science and fluid engineering.
The work positions magnetically reconfigurable ribbons as a promising path toward programmable fluidic architectures. By combining soft materials, embedded magnetic functionality and multistable mechanics, the researchers have shown how fluid control can be handled by geometry itself. For engineers exploring new methods of micro-scale liquid manipulation, this approach offers a compelling alternative to the more conventional hardware-heavy strategies seen today.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
