Constructing Biocompatible Devices Using Photo Bonding Adhesives

Fluidic channels structured in TMMF S2030 [Source: IMT]

Constructing devices that can be applied to cell adhesion and droplet control for digital PCR relies on the convergence of feature design and surface chemistry.

Innovative designs of devices for these biological applications can be created by structuring a class of photo-definable materials known as Photoimageable Bonding Adhesive (PBA). PBAs, which include polymers such as TMMF and Ordyl, can be photo-patterned to create complex fluidic channel systems for the capture and fusion of cells or droplets directly on a glass wafer by using standard MEMS processes [1].

This method is far more economical than typical hybrid approaches as it does not require extra passivation layers due to the availability of bio-compatible PBAs. Another important feature of PBAs is the well-defined material thickness and thickness variation making the material exceptionally well suited for automated tools used in a foundry, e.g. lamination tools, mask aligners and bonding tools. The combination of bio-functionalization and UV-adhesive sealing can lead to a cost-effective and up-scalable production of cell-trapping flow cells [2].

Benefits of PBAs

Incorporating a PBA in the microfluidic in vitro diagnostic device results in a higher utilization of the wafer space, because PBAs can be defined to create vertical walls and features with high aspect ratios. PBAs also allow for the integration of Ta₂O₅ and gratings, nano-wells, electrodes,with structured covalent bond chemistry within the flow cell channels.