kappa(κ)Chip: A modular microfluidic device for analyte screening using a parallelized assays and multiple shear rate approach

Abstract

Polymers are ubiquitous in the modern world, but many have low surface energies, making it difficult to engineer adhesive interactions to them. The large sequence space afforded by biology, and biology’s ability to evolve novel solutions to difficult problems, makes exploring bioinspired materials for novel adhesives attractive. However, the discovery of biologically inspired adhesive modalities requires the development of high-throughput screening methods that require small amounts of material, requirements for which microfluidics are ideally suited. In this work, we present the development of a novel microfluidic chip, the kappa(κ)Chip, which represents a significant leap in testing efficiency. The kappa(κ)Chip’s parallelized design enables 24 simultaneous adhesion tests from a single input stream. This drastically reduces experimental time and reagent consumption, and allows for more comprehensive data sets and the ability to quickly compare the performance of multiple proteins against different substrates – a capability unavailable with current single-test platforms. The chip was used to evaluate the adhesive properties of fungal hydrophobin proteins engineered to display on the surface of cells, using the adhesion of the cells as a proxy for hydrophobins ability to serve as an adhesive. The device combines microfabrication, microfluidics, material sciences, synthetic biology, Multiphysics simulation and ML in a unique way to enable the discovery of strong biological adhesives. Through the rapid screening enabled by the kappa(k)Chip, an informed rank-ordering of potential binding motifs/sequences against arbitrary substrates is achieved, and the device could also potentially be applied to studies of cell adhesion in tissue and organ environments, or marine fouling.