Sequentially pulsed fluid delivery to establish soluble gradients within a scalable microfluidic chamber array.

This work presents a microfluidic chamber array that generates soluble gradients using sequentially pulsed fluid delivery (SPFD). SPFD produces stable gradients by delivering flow pulses to either side of a chamber. The pulses on each side contain different signal concentrations, and they alternate in sequence, providing the driving force to establish a gradient via diffusion.

Continuously perfused, non-cross-contaminating microfluidic chamber array for studying cellular responses to orthogonal combinations of matrix and soluble signals.

We present a microfluidic cell culture array with unique versatility and parallelization for experimental trials requiring perfusion cultures. Specifically, we realize a rectangular chamber array in a PDMS device with three attributes: (i) continuous perfusion; (ii) flow paths that forbid cross-chamber contamination; and (iii) chamber shielding from direct perfusion to minimize shear-induced cell behaviour. These attributes are made possible by a bridge-and-underpass architecture, where flow streams travel vertically to pass over (or under) channels and on-chip valves.