Session: 13-01-01: Design and Fabrication, Analysis, Processes, and Technology for Micro and Nano Devices and Systems

Paper Number: 95512

95512 - Feasibility Study of Manufacturing 3d Microchannels Using 3d Printing and Bonding 

Three-dimensional (3D) printing as an additive manufacturing technique is promising for manufacturing not only 3D objects for health applications but also embedded 3D microchannels for microfluidic applications. Such embedded 3D microchannels have been manufactured using 3D printing with relatively large (hundreds of microns) features. However, 3D printing has shown limited repeatability for manufacturing relatively long microchannels and manufacturing small (less than 100 um) features has been only marginally possible using equipment of very high cost.

 

In this work, we present a cost-effective method for manufacturing embedded 3D microchannels using 3D printing and bonding. Microchannels, straight or serpentine, with the cross-sections down to 100 um and lengths more than 200 mm were designed with open microchannels in two parts with identical design. Passive alignment structures with three sets of pins and slots were added to the microchannels sides of each part, the pins on one side of the part and the slots on the other. A Formlabs Form 3 printer using low force stereography was utilized for 3D printing the open microchannels at a vertical orientation using clear resin. Different layer thicknesses were used with 25, 50, and 100 um. After 3D printing, the unexposed resin was washed away in the Form Wash setup filled with isopropyl alcohol (IPA), followed by air-drying of the samples. Then the two parts were aligned carefully using the passive alignment structures of pins and slots and clamped between two glass plates. The clamped assembly was placed in a UV Form Cure setup. Different UV curing times and temperatures (up to 80^oC) were tested.

 

Dimensional variations of the printed microchannels before bonding and after bonding are evaluated in terms of depths and widths as well as alignment accuracy of the bonding for the different printing layer thicknesses and the UV curing times and temperatures. Dye is pushed through the microchannels for visual inspection to verify if there is any leakage between the bonded parts. The pressure drop through the microchannels is characterized as a function of flow rates using a microfluidic pressure sensor. Through this feasibility study, minimum sizes for the microchannels and minimum gaps between the microchannels are identified for reliable manufacturing microchannels using the Form 3 3D printer.

 

Manufacturing 3D microchannels using 3D printing and bonding presented in this work requires additional bonding process steps, but allows for a cost-effective manufacturing method to realize relatively small and long microchannels for a variety of microfluidic applications.

Presenting Author: Daniel Park Louisiana State Univ

Presenting Author Biography: Daniel S. Park received his B.S. degree in Physics from Sung Kyun Kwan University, Seoul, Korea, in 1990, his M.S. degree in Electrical Engineering from Louisiana State University in 1999, and his Ph. D. degree in Electrical Engineering from the University of Texas at Dallas in 2004. He is currently a research associate at the Mechanical and Industrial Engineering and the Center for BioModular Multi-scale Systems (CBMM) in Louisiana State University, working on micromodel devices for enhanced oil recovery applications and BioMEMS devices/systems for biomedical applications. His research interests include micro/nano fabrication techniques and their applications to micromodels, BioMEMS, and nano-scale devices/systems.

Authors:

Daniel Park Louisiana State Univ
Jagannath Upadhyay SUNY Polytechnic Institute
Dimitris Nikitopoulos Louisiana State Univ