3D Printing of Monolithic Capillarity‐Driven Microfluidic Devices for Diagnostics

Abstract Rapid diagnostic testing at the site of the patient is essential when a fully equipped laboratory is not accessible. To maximize the impact of this approach, low‐cost, disposable tests that require minimal user‐interference and external equipment are desired. Fluid transport by capillary wicking removes the need for bulky ancillary equipment to actuate and control fluid flow. Nevertheless, current microfluidic paper‐based analytical devices based on this principle struggle with the implementation of multistep diagnostic protocols because of fabrication‐related issues. Here, 3D‐printed microfluidic devices are demonstrated in a proof‐of‐concept enzyme‐linked immunosorbent assay in which a multistep assay timeline is completed by precisely engineering capillary wetting within printed porous bodies. 3D printing provides a scalable route to low‐cost microfluidic devices and obviates the assembly of discrete components. The resulting rapid and seamless transition between digital data and physical objects allows for rapid design iterations, and opens up perspectives on distributed manufacturing.