In this study, economic magnetic tweezers (EMT) with a sharp gradient field were designed and built, in order to facilitate accurate force measurement. Our design costs less than 40 USD and is easy to mount onto most microscope stages. We leverage the computational fluidic dynamics techniques to calculate the forces based on the results obtained using our simple device. The EMT device is especially suitable to measure the traction forces at the dorsal side of a cell. As a proof of concept it was demonstrated that the EMT device could be applied to measure the dorsal traction forces exerted via the CD80-CTLA4 bond in metastatic cancer cells.
Keywords: 3D printing; CTLA4; biomedical engineering; dorsal traction force; drag force; force measurement; magnetic tweezers.