Turning light into flow: active matter driven microfluidic pumps*

Physiological processes like vascular remodeling and embryonic development occur under slow interstitial flow (around the scale of µm/s). Conventional microfluidic pumps rely on rigid, non-biocompatible materials, limiting their use in live-cell models. This project introduces a new paradigm for interstitial flow modeling by developing a biocompatible, programmable microfluidic pump powered by active matter. 

This system uses optically controlled solutions of microtubules and kinesin motors that contract under patterned 488 nm light to generate fluid flow. This enables programmable, microscale pumping with spatial and temporal precision that exceeds traditional microfluidic technologies. It is the first demonstration of using light activated active matter as a microfluidic component.

A predictive simulation model was used to evaluate designs in-silico. Two flow-generation strategies were explored: active matter contraction to produce local pressure gradients, and active matter driven deformation of a thin elastomeric membrane to displace fluid. Devices were fabricated via soft lithography and verified to fill and seal completely. Negative control trials with buffer and tracer beads showed negligible flow (0.0001–0.0021 µL/min), confirming that any flow observed results from active matter, not artifacts (Welch’s t ≈ –200.5, p < 10^-120). These results establish a framework for a programmable, biocompatible flow system that replicates physiological flow conditions.