Dynamic Dispensing – 3D Printing with Non-Newtonian Liquid Polymers

Our project was designed to perform two specific tasks that are used in our project sponsor’s (Neuraura Biotech) proprietary  neurosensor fabrication process. A secondary application of our project is that it can be used for rapid prototyping microfluidics devices. Some applications of Neuraura’s neurosensors are: measuring neuronal action potentials, observing cell-to-cell communication, stimulating areas of the brain, capturing appropriate signals for a brain-machine interface, and much more. These all help improve the quality of life for millions of individuals worldwide who are affected by brain diseases. Microfluidics, on the other hand, is a broad sector best known for the plethora of “lab-on-a-chip” devices that we use today for things like DNA analysis, drug delivery, and rapid test kits. Conventional lab-on-a-chip devices made from PDMS require expensive molds for each specific design, which makes prototyping novel devices time and cost intensive. With our system, these challenges can be eliminated.

Our system is the only one in the dispensing robot market that can dispense photoresists such as SU-8 in this drop-by-drop manner. Compared to other dispensing systems on the market, it offers 2-2.5 times the positional control and as much as 20-100 times better dispensed quantity control. These advancements are further complemented by its ability to handle and coat multiple geometries simply by creating the appropriate movement/dispensing profile for the structure. Furthermore, the technique used to dispense SU-8 in this manner is a novel concept where the industry standard for SU-8 application is spin coating the material onto a substrate.  

During the fall semester all our efforts were focused on planning and designing a feasible solution capable of printing non Newtonian liquid polymers. The system underwent rigorous testing to ensure the design met the standards agreed upon with the project sponsor in the product acceptance criteria. This work carried over into the winter semester, where we focused our efforts on building, testing, and validating our design. The testing itself was divided into 3 phases to minimize downtime, effectively address issues, and meet the promised standards. Testing results demonstrated our system’s ability to cut down the processing time and execute the tasks specified by the project sponsor consistently and accurately, per the tolerances agreed upon in the acceptance criteria. Our system is also cost-effective, and about 3-10 times cheaper than other market alternatives that offer lower accuracy and are limited in terms of the materials they can use. Check out the video above to see our design in action!

The entire system was designed and constructed during the quarantine period, which imposed meeting team restrictions and delayed procurement timelines. Regardless, we managed to design, build, test, and validate our system effectively. Therefore, the machine could be efficiently reproduced in a professional setting using the models, specifications, and directions the team has provided. Creating and operating multiple systems in tandem will also allow the sponsor to expand this system into an assembly line where each system could be responsible for a dedicated task (i.e. 1 system for SU-8 printing, 1 system for PDMS printing), improving the manufacturing efficiency. This, in conjunction with the SOPs provided, will allow even new users to familiarize themselves with the machine operation where they could then follow simple instructions to coat or create the required item. Overall, the feasibility of our solution was demonstrated by the ability to execute the tasks required by the project sponsor to the standard agreed upon in the product acceptance criteria at the start of the project.