3D Printed MRI Coils Fit Kids in Minutes

3D printed MRI coils are the classroom-and-clinic fabrication story this week: University of Southern California researchers can custom-size flexible receiver sensors for infants and children in under 10 minutes for about $30 in materials, according to 3D Printing Industry’s coverage. The point for readers is fit, not a new desktop gadget on a store shelf. Adult coils leave gaps on small bodies; a soft, printed antenna that matches the patient is meant to tighten the signal path. Treat contrast and cost claims as the research team’s until other hospitals publish matching numbers.

What's Happening

MRI coils act like antennas. After the scanner’s magnet and radio-frequency pulse, they pick up the body’s weak return signal. The tighter the coil sits against the anatomy, the stronger that signal tends to be. Most commercial coils are built for adult sizes. On an infant or a quickly growing child, a loose fit weakens the image. Custom hardware has historically meant thousands of dollars and months of lead time — useless when a patient’s shape changes in weeks.

Yasser Khan’s lab at the USC Michelson Center spent about three years printing conductive silver ink onto a thermoplastic elastomer with skin-like stretch of roughly 5% to 10%. Dimensions start as a digital file, so a new size is a reprint, not a tooling order. Krishna Nayak’s Dynamic Imaging Science Center supplied motion-aware MRI methods and a specialized scanner environment; John Wood at Children’s Hospital Los Angeles guided where pediatric and fetal cardiac work hurts most. USC and trade press cite roughly four times the image contrast of standard commercial coils in testing, and potential for fast-moving anatomy such as a beating heart. Those figures are theirs, not an FDA clearance summary.

The peer-reviewed backbone is a Nature Communications paper on rapid 3D printed flexible coils for dynamic wrist and heart imaging at 0.55 T. That study fabricated four-element wrist arrays in about eight minutes per element at roughly $30 in consumables, reported up to fourfold contrast and fivefold sharpness gains versus a commercial coil in dynamic wrist imaging, and showed a seven-element silver-ink cardiac array with cine quality comparable to a commercial body coil. The September trade story extends the same digital-fabrication idea toward infants — same lab family, same fit problem, still research hardware plugged into existing MRI electronics.

Why This Matters for Educators and Lab Makers

If you teach or run a makerspace next to a biomedical lab, this is a materials-and-process lesson more than a product launch. The hard part was not “print a spiral.” It was finding a silver ink and elastomer stack that stays conductive enough while stretching a few percent, then wiring custom electronics to a real scanner. That is digital manufacturing for a regulated environment: change the CAD, reprint the antenna, keep the hospital’s magnet and pulse sequences.

It also clarifies what desktop polymer printers are for and what they are not. A student project that prints a soft sensor substrate is adjacent to this work. A student project that claims to replace a clinical coil pack is not. The useful takeaway for hobbyists and small shops is the design pattern — anatomy-specific digital files, soft materials, and iteration measured in minutes — not a shopping list for MRI-grade silver ink. Structural continuous-fiber parts answer a different question: hold load, not pick up RF.

How Patient-Specific Coil Fabrication Differs From Desk Printing

Aspect	USC flexible MRI coil workflow	Typical desktop FFF / continuous-fiber print
Primary job	Receive RF signal close to anatomy	Make a solid polymer or composite part
Key material	Conductive silver ink on stretch elastomer	Thermoplastic filament; optional continuous tow
Fit requirement	Conform and move with skin (~5–10% stretch cited)	Dimensional accuracy and stiffness at room temp
Iteration loop	Resize digital layout; reprint in minutes	Reslice CAD; reprint fixture or bracket
Success metric	SNR, contrast, patient comfort in scanner	Strength, fit-up, cycle time on the bench

What the Research Says

Muñoz and colleagues demonstrated high-quality dynamic imaging at 0.55 T with coils made by direct-ink-write silver printing and by screen printing copper-doped eutectic gallium-indium. Wrist arrays fabricated in about eight minutes per element at roughly $30 in consumables delivered up to four times higher contrast and five times greater sharpness than a commercial coil during dynamic wrist imaging in their subjects, while a silver-ink cardiac array produced cine images comparable to a commercial coil. The paper frames flexible, digitally defined receivers as a way to recover signal when low-field and accelerated dynamic scans otherwise lose SNR (Muñoz et al., 2026).

Motovilova and co-authors compared casting and direct-ink-writing routes for dual-channel stretchable liquid-metal MRI coils. Direct-ink-writing won on fabrication speed, accuracy, repeatability, and thinness (about 0.6 mm). Bench tests held resonance near 128 MHz across 0% to 30% stretch, and the stretchable array was more conformal than a commercial knee coil with about 50% higher SNR in the region of interest in their comparison. That work sits upstream of USC’s silver-ink path: same problem of soft, stretchable conductors, different metal and process details (Motovilova et al., 2023).

Frequently Asked Questions

What are 3D printed MRI coils, and why print them?

MRI coils are antennas that pick up the body’s weak radio signal after a magnet and RF pulse. A closer, better-fitting coil usually means a clearer image. Adult-sized rigid coils leave air gaps on infants. Digitally fabricating a soft, patient-sized coil aims to shrink that gap without waiting months for a custom factory part. Treat reported contrast and cost figures as the research team’s until clinics replicate them.

How fast can USC’s flexible MRI sensors be made?

USC and 3D Printing Industry report coils custom-made in under 10 minutes for about $30 in consumables, with stretch of roughly 5% to 10% on a thermoplastic elastomer. The Nature Communications study describes about eight minutes per wrist-array element at a similar consumable cost. Those times are lab fabrication of the conductive path, not a full hospital clearance cycle.

Can a desktop continuous-fiber printer make MRI coils?

No. USC’s process prints conductive silver ink onto a soft elastomer so the antenna can flex with skin. A continuous-fiber desktop printer lays a polymer matrix with a continuous tow for structural parts. Different materials, different electronics, and different regulatory paths. Do not treat a composite fixture printer as an MRI coil factory.

Fibricate's Place in This Story

Soft RF antennas and continuous-tow brackets share a digital-file habit and little else. Companies like Fibricate, whose FibreSeeker 3 continuous carbon fiber 3D printer co-extrudes polymer with a continuous tow from feedstock such as the continuous carbon fiber spool, sit on the structural side of that split: jigs, covers, and load paths that have to survive at room temperature. USC’s coils sit on the electronics side: stretch, conductivity, and scanner integration. Use the MRI story to teach why material choice follows the job. Do not pitch a composite desktop printer as a substitute for a silver-ink receive array.

What to Watch Next

Watch for multi-site imaging studies on infants and children, not just wrist and adult cardiac volunteers, and for how hospitals handle sterilization, connector standards, and regulatory labeling. Over the next 12–24 months, expect more medical device papers to treat patient-specific digital fabrication as a manufacturing method rather than a one-off prototype trick. The signal for makers and STEM labs is whether soft printed sensors stay a research niche or become a repeatable clinic workflow with published failure modes — that is when the “under 10 minutes” claim either holds up or gets a quieter footnote.

References & Further Reading

1. Muñoz, F., et al. (2026). Improved dynamic MRI of the wrist and heart at 0.55 T enabled by rapid 3D printed flexible coils. Nature Communications.
2. Motovilova, E., Ching, T., Vincent, J., Shin, J., Tan, E. T., Taracila, V., Robb, F., Hashimoto, M., Sneag, D. B., & Winkler, S. A. (2023). Dual-Channel Stretchable, Self-Tuning, Liquid Metal Coils and Their Fabrication Techniques. Sensors.
3. USC Team 3D Prints Custom MRI Sensors for Infants in Under 10 Minutes. 3D Printing Industry. Retrieved September 8, 2026.