Refreshable microfluidic channels constructed using an inkjet printer

This paper describes microfluidic channels that can be erased and then reconstructed. These channels were constructed between two stacked glass slides. These slides had ground and hydrophobic surfaces, and a line had previously been drawn on their surfaces using an inkjet printer with a water-soluble liquid as its “ink”. A water solution was injected between the slides, and it flowed along the previously drawn line by itself. Thus, a channel filled with the solution was formed, though there was no real groove on the slides. We investigated the application of various liquid materials as the “ink” based on their viscosity, boiling point, solubility in water, etc. A suitable material was 2-(2-ethoxyethoxy)ethanol. The channel width that we could obtain ranged from 470 to 3000 μm. We could rapidly construct straight, curved, and crossed channels. In addition, we could erase these channels by rinsing with acetone and then reconstruct them using the same procedure.