High-Throughput Plastic Microfabrication Technologies for Smart Lab-on-a-Chips

DESCRIPTION (provided by applicant): The objective of this revised fast-track effort is the development of reliable, high-throughput microfabrication techniques for production of lab-on-a-chip for Point-of-Care Testing (POCT) applications. The proposed fabrication processes will significantly improve the throughput of plastic lab-on-a-chip manufacturing processes while making the process more reliable. The processes developed in this work will allow (a) Siloam to successfully commercialize lab-on-a-chip applications under development and (b) serve as cornerstone of development for the BioMEMS industry by offering fully-automated processes for lab-on-a-chip fabrication. The current plastic lab-on-a-chip production processes include a mix of processes with varying throughput. Low-throughput processes such as drilling, dicing, microfluidic interconnect assembly present significant bottlenecks to the high-throughput desirable of production processes. This effort proposes a systematic development of plastic microfabrication processes that can completely eliminate the low-throughput processes. Furthermore, the newly developed process sequence will allow for a fully-automated process flow which can dramatically enhance the throughput as well as reliability of a production process. During Phase I efforts, research efforts will focus on development of the high-throughput plastic microfabrication processes. A double-side injection molding process is proposed that can enhance the functionality of the injection molding process by allowing for fabrication of (a) through-holes geometries (eliminates drilling), (b) automatic definition of chip size (eliminates dicing), and (c) self-alignment during assembly (increases accuracy and reliability). Also, a novel mechanically-assisted thermoplastic fusion bonding protocol is proposed which can dramatically increase the throughput for the bonding step (few seconds per device). This process relies on a high density array of interlocking pillar-hole structures (fabricated using double-side injection molding) which allows for rapid chip assembly (at room temperature). Following assembly, a batch of assembled chips is simultaneously annealed (at high temperature) which leads to chemical bond formation across the interface. Finally, self-aligning microfluidic interconnects which can be incorporated as a part of the assembly process will be developed. A multi-layer microfluidic device using all of the above processes will be fabricated as a proof-of-concept demonstration vehicle. During Phase II efforts, the merit of the newly developed fabrication processes will be demonstrated by fabrication of lab-on-a-chips for specific BioMEMS applications. The use of the new technology will (a) either improve existing microfluidic devices or; (b) make possible microfluidic devices that were not possible with current fabrication processes. POCT diagnostic tools, using disposable lab-on-a-chips will allow for frequent patient monitoring leading to more informed and clinically relevant decisions from physicians. The manufacturing processes proposed in this work, for microfluidic lab-on-a-chips, are crucial for successful commercialization of this technology.