To enable multiplexed assays on paper-based biosensors, it is important to deliver different reagents sequentially, or in other words, to achieve timed/programmed fluid delivery. Speedup fluid flow in paper substrates has been a challenge since the natural 3D structure of cellulose fiber network was zigzagging and tortuous, which make it difficult for microflow front to proceed. Recent study has shown the interesting utility of the microflow channels created by laser etching to mitigate the challenge. They have used a CO2 laser to create etched grooves on paper, which can accelerate wicking speeds in paper-based microfluidic devices. This technique enables rapid, sequential delivery of sample and wash buffer and allows for singlestep fabrication of paper-based microfluidic channels. Sealing grooved channels with tape made them wick faster, while sealing methods such as lamination had a negative effect on wicking. This simple process of etching grooves in paper requires no additional materials or chemicals and has potential for more sophisticated paperbased microfluidic devices in the future.