Microembossing: A Convenient Process for Fabricating Microchannels on Nanocellulose Paper-Based Microfluidics

Our research introduces Nano paper as an innovative substrate in contrast to conventional paper. Nano paper offers optical transparency, exceptional smoothness, and chemical adaptability. Now our substrate, it currently lacks an efficient microchannel fabrication method, limiting its broader adoption in microfluidics.

The progression of manufacturing technologies, including laser cutting and micro or Nano 3D printing, has significantly improved motor precision. Consequently, it has simplified and enhanced the precision of microfluidic fabrication. Additionally, the images of innovative substrate materials, like Nano cellulose paper, has further elevated the performance of paper-based analytical microfluidic devices.

Currently, one of the experimental challenges we face is laser-cutting processing, which limits most widths to 200 micrometers and impacts microchannel accuracy. To all companies, future research will explore Nano 3D printing for mos aiming to achieve a higher processing level in Nano paper based analytic called microfluidic devices. In contrast to established techniques for microchannel fabrication on Nano cellular paper, such as 3D printing, 3D coating or manual cutting and assembly, our method offers a distinct advantage.

It combines simplicity with superior accuracy, ensuring user friendliness, cost effectiveness, time efficiency, and the attainment of micrometer level macro channels. Our findings provide a new, accurate and simple method to fabricate micro channels on Nano paper and eventually for making Nano paper based microfluidic devices. In the big picture, with this method, the existing paper substrate Nano paper can be easily used in the field of microfluidics.

To begin, laser cut the 500 micrometer thick Polyetrafluorethylene or PTFE films using the laser cutting machine to generate the microchannel mold. Disperse four grams of tempo oxidized Nanofibrillated cellulose gel in distilled water. Stir the suspension heavily at 120.8 G for 30 minutes until no cellulose flock is seen.

Vacuum filter the clear suspension to obtain a Nano paper gel. Next, place the PTFE mold on the surface of the Nano paper gel. Use a hot press to emboss the gel for 10 minutes under 750 kilopascals pressure at 50 degrees Celsius.

To release the mold, peel off an additional layer of filter Nano paper gel from the filter membrane. Attach the peeled layer on top of the embossed Nano paper gel and stack the two layers to create a hollow microchannel structure. Dry the stacked layers in a drying oven at 75 degrees Celsius for 30 minutes.

Next, prepare the Nano pads with straight and curved channels. Add red and blue droplets in the inlet zone simultaneously allowing automatic channel flow through. Micro channel patterning at 200 micrometers was possible with micro embossing.