Dry reagent storage in dissolvable films and liquid triggered release for programmed multi-step lab-on-chip diagnostics

Multi-step lab-on-chip assays typically require multiple manual pipetting steps of different reagents and a sophisticated design to run the assay, which is generally unfavorable for point-of-care applications. This work presents the use of dissolvable polyvinylalcohol films for (1) reagent storage and release together with (2) timed valving in capillary driven microfluidics. This allows four different volumes to be split up from a single liquid which is applied to the inlet of the chip. PVA captured reagents are released to each volume forming four different solutions which are separately released in a timed sequence to a common target zone. The presented chip thereby enables a single liquid-triggered multi-reagent sequence with the potential to be used for advanced point of care diagnostics.