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Device Technologies and Biomedical Robotics

Device Technologies and Biomedical Robotics - Poster Session B

Poster I18 - Engineering a Cost-Effective Alternative to Dip Coating Equipment for Laboratory Use

Thursday, October 24, 2024

2:45 PM - 3:45 PM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Teresa M. Hawk

Undergraduate Student
University of Cincinnati
Lewis Center, Ohio, United States

Co-Author(s)

JK

Jonathan R. Kindig, MA

Undergraduate Student
University of Cincinnati, United States
KB

Karina A. Bruce

Graduate Student
University of Cincinnati
Cincinnati, Ohio, United States

Last Author(s)

JM

John R. Martin, PhD

Assistant Professor
University of Cincinnati, United States

Introduction: Equipment cost is a major barrier to overcome for many institutions conducting research. Much of the commercially available laboratory equipment is expensive, lacks versatility, and has limited opportunities for alterations, leading many institutions to be unable to justify the expenses. This factor has limited many groups’ research efforts. In this work, we demonstrate a cost-effective, custom-made dip coating machine for layer-by-layer (LbL) coatings. LbL coatings are formed by depositing alternating cations and anions on the surface of various substrates. These coatings can house various therapeutics that can be employed in numerous regenerative medicine applications. As these coatings are too time consuming to do by hand and current equipment lacks the ability to coat various substrates, a custom device was constructed.

In this project we have designed and implemented an affordable dip coating machine that meets the needs of the laboratory while using consumer grade, off-the-shelf components with easily manufactured custom fixturing. This newly designed system is versatile, easy to operate, and most importantly allows for the progression of research into novel drug-loaded coatings.

Materials and

Methods: Requirements for the Machine
A list of requirements for the new equipment was established by consulting the laboratory staff. Major requirements for the system revolved around both the needs of the group, alongside addressing the lack of versatility and capabilities of commercially available equipment. Notable pitfalls of commercially available options include a limited number of stations, the inability to program extended dip cycles, and various physical constraints such as size and weight.

Machine Fabrication
Most of the materials required for machine fabrication were off-the-shelf components that could be easily sourced from Amazon, McMaster Carr, and other online retailers. The machine was constructed using equipment available at the 1819 Innovation Hub in Cincinnati, Ohio, including a drill press, sand blaster, water jet cutter, FDM printers, and hand tools.

Results, Conclusions, and Discussions: The final design can be seen in Figure 1. A simple two axis design was selected. The two axes are driven by a belt drive linear rail on the x-axis which allows for faster movement and a screw drive on the y-axis to minimize the effect of the load of the test articles on its accuracy. The linear rails are fitted to a powder coated base made of 6061 aluminum alloy. The frame holds an acrylic plate to position multi-well basins, allowing for precise alignment and quick, efficient positioning. The frame supports the housing for the electronic components. Bipolar stepper motors driven by A4988 stepper drivers were selected to run the linear rails due to their high accuracy and ease of use. Finally, an appropriate power supply, monitor, and voltage converters were selected.

A Libre Renegade single board computer was selected to drive the system. This component provides support for a basic Linux-based operating system which can run standard python code and the connection of additional storage drives to hold extensive programs. When developing the software, custom libraries were created to allow the single board computer to communicate with the motors and the monitor. A custom user interface was developed using PyQt5 that allows the operator to enter custom test programs. Back-end code was implemented to save these programs and translate them to the needed motor movements.

The completed machine (Figures 2 and 3) was delivered to the lab for testing. Throughout the process, several design changes were needed to improve ease of manufacturing and support usage. As the development of this equipment progresses, there are several avenues which could be explored to further improve the equipment.

Conclusion
We successfully designed and fabricated a dip coating machine within the specified budget that could be used by the lab to conduct research activities. The total cost of one machine is less than $1,000. Current design iterations allow for the coating of silicon wafers, orthopedic hardware, and many other substrates. Future iterations will continue to expand the capabilities of this device, improve research initiatives, and break down financial barriers in research.

Acknowledgements (Optional):