TY - JOUR
T1 - Fabrication of a microfluidic device by using two-photon lithography on a positive photoresist
AU - van der Velden, Gijs
AU - Fan, D.
AU - Staufer, U.
PY - 2020
Y1 - 2020
N2 - Organ-on-chip (OoC) technology is increasingly used for biomedical research and to speed up the process of bringing a drug from lab to the market. The main fluidic components of an OoC device are microfluidic channels and porous membranes arranged in three dimensions. Current chips are often assembled from several parts. In the development phase a small change in design will cause a delay in the research because a new prototype has to be built and assembled again step-by-step. The research discussed in this paper addresses this point by targeting a monolithic 3D device that can be fabricated in a single lithography and development step, enabling rapid prototyping. Two-photon lithography (TPL) was used in combination with a positive photoresist AZ 4562. The exposure process was characterized, which included an experimental and theoretical study of the voxel size and shape. It was found that the voxel has an hourglass-shape for the laser power settings that were required for process stability. The smallest pores we could produce with these settings measured 250 nm in diameter. The TPL process was then used to fabricate a microfluidic device featuring two crossed channels each one on a separate height-level, connected by a membrane in the centre. Access to the channels was provided through 4 reservoirs from the top-side of the device. The device was successfully filled with water and dried to see whether it can withstand the corresponding capillary forces.
AB - Organ-on-chip (OoC) technology is increasingly used for biomedical research and to speed up the process of bringing a drug from lab to the market. The main fluidic components of an OoC device are microfluidic channels and porous membranes arranged in three dimensions. Current chips are often assembled from several parts. In the development phase a small change in design will cause a delay in the research because a new prototype has to be built and assembled again step-by-step. The research discussed in this paper addresses this point by targeting a monolithic 3D device that can be fabricated in a single lithography and development step, enabling rapid prototyping. Two-photon lithography (TPL) was used in combination with a positive photoresist AZ 4562. The exposure process was characterized, which included an experimental and theoretical study of the voxel size and shape. It was found that the voxel has an hourglass-shape for the laser power settings that were required for process stability. The smallest pores we could produce with these settings measured 250 nm in diameter. The TPL process was then used to fabricate a microfluidic device featuring two crossed channels each one on a separate height-level, connected by a membrane in the centre. Access to the channels was provided through 4 reservoirs from the top-side of the device. The device was successfully filled with water and dried to see whether it can withstand the corresponding capillary forces.
KW - Microfluidic channel
KW - Organ-on-Chip
KW - Positive photoresist
KW - Two-photon lithography
KW - Voxel shape
UR - http://www.scopus.com/inward/record.url?scp=85083816801&partnerID=8YFLogxK
U2 - 10.1016/j.mne.2020.100054
DO - 10.1016/j.mne.2020.100054
M3 - Article
AN - SCOPUS:85083816801
SN - 2590-0072
VL - 7
JO - Micro and Nano Engineering
JF - Micro and Nano Engineering
M1 - 100054
ER -