Robust and Biocompatible Bonding of Hybrid Microfluidic Devices Using Off-Stoichiometric Thiol-ene Thermosets

Abstract: Some of the major obstacles the microfluidics industry has yet to overcome in order to facilitate large scale manufacturing of devices are costly back-end processes. Among these, bonding presents some of the most obvious difficulties and is often associated with structural deformation and surface modification. Off-stoichiometric thiol-ene (OSTE) is a relatively new material and hasn’t yet achieved the same level of adoption as Polydimethylsiloxane (PDMS) which has been the go-to material in the field of microfluidics for over two decades. OSTE offers an alternative to PDMS and promises bonding without surface treatment as well as a hydrophilic surface, removing a step in the manufacturing process. In this work, the property of OSTE to bond with a variety of commonly used thermoplastic materials were tested as well as its suitability for use in pharmaceutical devices such as Lab-on-a-chip. In addition to untreated OSTE, a surface modifier was used to examine the potential for surface modification when using OSTE as a microfluidics material. From the testing performed, we demonstrated OSTE’s capacity to form robust bonds with a range of thermoplastic materials as well as comparable biocompatibility to PDMS.