BME Master's Final Exam Announcement for Maxwell Mensah (J. Linnes, advisor)

Everyone is invited to attend the public presentation beginning at 10:00 AM.

Title: Automating Scalable Manufacturing of Point-of-Care Paper Based Nucleic Acid Detection Tests

Date: June 13, 2025

Time: 10:00 AM

Location: MJIS 2001 and Zoom - https://purdue-edu.zoom.us/my/jlinnes

Advisory Committee: Jacqueline Linnes, Chair; Ramses Martinez; Marina Sala De Medeiros

Abstract:

Molecular point-of-care (POC) diagnostics have revolutionized the urgent detection of infectious diseases or sample testing directly at the patient’s location, without involving advanced and costly laboratory equipment and specialized training. However, manual assembly of key components presents significant limitations such as labor cost, inconsistent alignment accuracy, increased risk of damage to delicate components, materials waste, and low throughput. These challenges are particularly difficult in paper-based devices with small, difficult to handle components, and the issues hinder the scalability of paper-based POC device manufacturing. To address this gap, a novel pick-and-place assembly system was designed and validated using a Dobot MG400 robot fitted with a vacuum-backed single-head end effector silicone rubber suction cup. This allowed for the assembly of key paper-based diagnostic components such as lateral flow immunoassays (LFIAs) and thermally actuated wax valves, as well as a polyethylene terephthalate glycol (PETG) sample cup into an integrated disposable cassette. Our key findings showed precise component alignment, denoted by a horizontal side-by-side and vertical overall average displacement of 0.5mm ± 0.38mm and 5.1mm ± 0.34mm, respectively, and no damage on the LFAs membranes. The cassette was optimized to performed reverse-transcription loop-mediated isothermal amplification (RT-LAMP) amplifying Hepatitis C Virus (HCV) RNA on a hot block at a temperature of 63ºC and enable readout in an LFIA by opening the wax valve at temperatures between 80ºC and 95ºC. The cassette design prevented sample leakage and aided consistent sample flow from the PETG cup onto the LFIA membrane for results visualization. Chemical compatibility tests conducted demonstrated no adverse effects of the cassette materials on the HCV samples. At a total assembly time of 2.5 minutes, an array of 9 disposable cassettes we can significantly enhance assembly accuracy, repetition, and output by integrating collaborative robotics into POC diagnostics production in order to eliminating the challenges faced during scalability and early prototyping stages.