title: Rollable Microfluidic Systems with Microscale Bending Radius and Tuning of Device Function with Reconfigurable 3D Channel Geometry.
abstract: Flexible microfluidic system is an essential component of wearable biosensors to handle body fluids. A parylene-based, thin-film microfluidic system is developed to achieve flexible microfluidics with microscale bending radius. A new molding and bonding technique is developed for parylene microchannel fabrication. Bonding with nanoadhesive layers deposited by initiated chemical vapor deposition (iCVD) enables the construction of microfluidic channels with short fabrication time and high bonding strength. The high mechanical strength of parylene allows less channel deformation from the internal pressure for the thin-film parylene channel than bulk PDMS channel. At the same time, negligible channel sagging or collapse is observed during channel bending down to a few hundreds of micrometers due to stress relaxation by prestretch structure. The flexible parylene channels are also developed into a rollable microfluidic system. In a rollable microfluidics format, 2D parylene channels can be rolled around a capillary tubing working as inlets to minimize the device footprint. In addition, we show that creating reconfigurable 3D channel geometry with microscale bending radius can lead to tunable device function: tunable Dean-flow mixer is demonstrated using reconfigurable microscale 3D curved channel. Flexible parylene microfluidics with microscale bending radius is expected to provide an important breakthrough for many fields including wearable biosensors and tunable 3D microfluidics.
authors.affiliation: Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Jihye
authors.identifier: http://orcid.org/0000-0001-8546-854X
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Jae Bem
authors.initials: JB
authors.lastname: You
authors.affiliation: Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Nam
authors.affiliation: Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Sumin
authors.initials: S
authors.lastname: Seo
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.|KAIST Institute for NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Sung Gap
authors.identifier: http://orcid.org/0000-0001-7562-2929
authors.initials: SG
authors.lastname: Im
authors.affiliation: Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.|KAIST Institute for NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Wonhee
authors.initials: W
authors.lastname: Lee
keywords: flexible microfluidics; inertial microfluidics; initiated chemical vapor deposition; parylene microfluidics; rollable microfluidics