An infant's heart can be about the size of a walnut, and it changes shape fast. Most MRI coils, the antenna-like loops that pick up the signal during a scan, come in adult sizes. That mismatch is exactly the kind of problem 3D printing was built to solve, and this week a University of Southern California team showed how far that idea can go: a custom-fit MRI coil, printed in under 10 minutes, for about $30.
We build custom parts every day here in Rockville, MD, so we read this one closely. Below is what the USC team actually did, what it changes, and what it means if you have a part that needs to fit one specific thing (or one specific person) and nothing else.
What USC built, in plain terms
According to USC's announcement and coverage by 3D Printing Industry this week, a team led by Yasser Khan at the USC Viterbi School of Engineering developed flexible MRI receive coils that can be customized to an individual patient and 3D printed in less than 10 minutes for roughly $30 each. In testing, the coils produced about four times the image contrast of standard commercial coils. The work was published in Nature Communications and involved the USC Michelson Center for Convergent Bioscience and Children's Hospital Los Angeles.
The manufacturing recipe took about three years to land. The team prints conductive silver ink directly onto a thermoplastic elastomer, a soft material with properties close to human skin. The finished coil stretches roughly 5 to 10 percent, so it follows the body instead of sitting stiffly on top of it. They also had to build custom electronics to connect these unusual coils to an existing MRI system.
The part everyone should pay attention to is not the silver ink. It is the workflow. Because each coil starts as a digital file, a researcher can change the size or shape on a computer and print a fresh one right away, rather than waiting months for a specialized part to be manufactured. Khan's comparison is a camera lens: use a big lens on a tiny subject and you get a blurry picture. Tailor the lens to the subject and the image gets sharp.
Why the "10 minutes and $30" part matters more than the MRI part
Custom medical equipment has always been possible. What made it rare was cost and lead time: thousands of dollars and months of waiting for something that might not fit by the time it arrives, because the patient grew. USC did not invent a new physics trick so much as they collapsed the economics of a one-off part until it became a routine one.
We see the same shift in ordinary industrial work. When the part is a file and the setup is zero, the question stops being "can we afford a custom part" and becomes "what dimensions do you need."
I need a part that fits one specific object exactly. Can a 3D printing shop make just one?
Yes. A 3D printing shop can make a single custom-fit part from a scan or a drawing with no minimum order, because there is no mold or tooling to pay off. That is how USC can print one coil for one child, and it is how we handle a bracket for one discontinued appliance, a cradle for one odd-shaped instrument, or a housing for one prototype board. The steps are the same either way: capture the geometry (calipers, a drawing, or a 3D scan), model the part around it, print, check fit, and adjust if needed.
If the thing your part has to fit is irregular, a handheld 3D scan is the fastest way to get an honest model of it. That is the core of our 3D scanning and reverse engineering service: scan the real object, build clean CAD from it, and print a part that matches what actually exists rather than what a drawing from 1998 says should exist.
My part needs to change size every few months. Do I have to pay for new tooling every time?
No. When a part is printed from a digital file, you change a dimension in the file and print again, and there is no tooling to remake. USC's own example is a growing child who needs a slightly different coil as the body changes. In our shop the same pattern shows up as a product enclosure that grows a few millimeters between prototype rounds, a fixture that has to move as the assembly line changes, or a replacement part where the first version was close but not perfect. Version two is a parameter edit, not a new project.
For engineering buyers, this is the practical argument for keeping parts as editable CAD rather than a pile of STL files. We model parts with named dimensions so the next revision is a one-line change, not a redesign fee.
What this does not mean
A few caveats. USC's coils are research devices, not something a hospital can order today, and nothing here is medical advice. And "custom-fit" only works if the input geometry is right: a guessed dimension produces a fast, cheap part that does not fit. Measure first, print second.
How we use the same playbook in Rockville
Our shop runs the scan, model, print loop for makers, small manufacturers, and engineering teams who need one part, or a few dozen, without a minimum order or a tooling invoice, in materials from PLA and PETG up to PEEK and ULTEM. If you want a part built and shipped rather than a quote and a maybe, start at Build and Ship or email info@dcadditivepros.com with a photo, a sketch, or the part you need matched. Brands with a scanner or flexible material they would like us to put through a real custom-fit job can reach us at the same address.
Frequently asked questions
I have an object with no drawings. Can you 3D scan it and print a part that fits it?
Yes. We scan the object, build CAD from the scan, and print a part that matches the real geometry. Irregular or worn parts are exactly where scanning beats measuring by hand.
How much does a one-off custom 3D printed part cost?
It depends on size, material, and how much modeling is needed, but there is no tooling charge and no minimum order. Small fit-critical parts often cost less than the shipping on an OEM replacement. Send a photo and dimensions for a quote.
Can a 3D printed part be resized later without starting over?
Yes, if it was modeled with editable dimensions. We keep the CAD so a later size change is a quick edit and a reprint, not a new design fee.
Do you print flexible parts like the USC coil?
We print flexible parts in TPU and similar elastomers for grips, gaskets, and cushions. We do not print conductive silver ink or medical devices; the USC work is a research process, not a service we offer.