3D Printable Elastomer That Survives Yank and Wear

A new 3D printable elastomer from EPFL’s Soft Materials Lab targets the soft-part failure mode makers know well: the print that either tears on one hard yank or slowly cracks after hundreds of flexes. In a Science Advances study, double network granular elastomers combine much higher fracture toughness with improved fatigue resistance by redistributing strain into softer regions. For garage and shop printers, the practical takeaway is clearer material job-matching — soft skins versus load-bearing frames — not a claim that every FDM spool just got tougher overnight.

What's Happening

According to New Atlas coverage of EPFL’s resilient polymer work, Eva Baur, John Kolinski, and Esther Amstad report that double network granular elastomers (DNGEs) — stiff elastomer microparticles linked by a softer second network — can reach fracture toughness up to about 15 times that of comparable elastomers and fatigue resistance up to about three times higher. When stretched, stress shifts toward soft interstitial zones where polymer chains rearrange and dissipate energy instead of snapping bonds. Cracks are forced to wander through soft regions rather than cleave straight across.

The team previously introduced printable DNGEs in 2024 as inks for structures with locally tuned stiffness. Amstad notes the original goal was processability; toughness and repetitive energy dissipation showed up as architectural bonuses. Applications flagged in the paper include soft robotics, wearables, and biomedical devices that must stretch without becoming disposable after a few load cycles. The researchers also point toward more sustainable formulations without giving up mechanics.

Why This Matters for Makers and Small Shops

Everyday soft prints — phone grips, gasket prototypes, wearable straps, robot skin demos — usually live on TPU or similar FFF elastomers. Those materials already stretch; what they do not always do is survive both a sudden over-extension and months of repetitive bending. Fatigue resistant soft materials research matters because product-like prototypes fail in the field more often from cycling than from a single tensile test coupon.

The honest hardware bridge: DNGE inks are not the same as buying a TPU spool. Treat the headline as a materials literacy upgrade. Soft outer geometry can stay elastomer; anything that clamps, mounts, or carries torque still wants a stiffer polymer path. That split is how desktop workflows absorb lab advances without pretending a consumer FDM nozzle suddenly prints Science Advances formulations.

When Soft Prints Need Different Jobs

• Single-shock survival. Door-slam, drop, or hard pull — prioritize toughness so cracks do not race across the part.
• Repeated flexing. Hinges, bellows, and straps fail from fatigue; look for architectures that dissipate energy repeatedly.
• Local stiffness maps. Soft skin around a firmer “bone” region — the 2024 DNGE print demos showed why composition gradients matter.
• Standard FFF TPU. Still the practical desktop choice for flexible everyday parts until specialty elastomer inks are commercialized.
• Load-bearing frames. Brackets and fixtures that hold soft assemblies need directional strength beyond elastomer stretch.
• Lab vs garage process. DIW microparticle inks require different rheology and printers than fused filament — do not mix process claims.

What the Research Says

Baur and colleagues show that DNGEs composed of stiff elastomer microparticles connected through a softer second network can combine toughness with fatigue resistance — a pairing single-network elastomers and many tough multinetworks struggle to hold at once (Baur et al., 2026). Locally varying composition helps deconcentrate stress and repeatedly dissipate energy at moderate strains, which is why the authors argue the architecture suits soft robotics and wearables limited by the stiffness–toughness–fatigue trade-off.

That 2026 result sits on their earlier Advanced Materials demonstration that DNGEs can be 3D printed with locally varying ultimate tensile strain and stiffness, including finger-like demos with rigid “bones” inside softer skins (Baur et al., 2024). Together the papers separate two claims: printable spatial property control, then measured fracture and fatigue gains from the same granular double-network idea. Neither paper turns a stock FDM printer into a DNGE machine; both sharpen what “soft but durable” should mean when labs design elastomer inks.

Frequently Asked Questions

What is a 3D printable elastomer like EPFL’s DNGE?

A 3D printable elastomer here means a rubber-like ink that can be extruded into soft parts. EPFL’s double network granular elastomers embed stiff elastomer microparticles in a softer network so the print can stretch, absorb energy repeatedly, and resist both sudden fracture and gradual fatigue better than many single-network soft materials.

How do fatigue resistant soft materials differ from tough ones?

Tough elastomers often survive a hard pull but accumulate damage under repeated flexing. Fatigue resistant soft materials do the opposite trade-off more often: they last under cycling but can snap under a shock. DNGE research aims to improve both fracture toughness and fatigue resistance in one printable architecture.

Can I print double network granular elastomers on a normal FDM printer?

Not as a drop-in filament spool. Published DNGE workflows use microparticle-based inks for direct ink writing on capable printers, not standard PLA/TPU FFF. Hobby FDM owners should treat the science as a design lesson — match soft-skin jobs to TPU and keep load paths in stronger materials — until commercial DNGE filaments exist.

Fibricate's Place in This Story

DNGE is a soft-materials and ink architecture story. Fibricate enters when a soft prototype needs a jig, clamp, or end-effector frame that must stay dimensionally honest while the elastomer stretches. Companies like Fibricate, whose FibreSeeker 3 continuous carbon fiber 3D printer co-extrudes continuous fiber for directional polymer strength, and supplies such as the continuous carbon fiber spool, fit that supporting role. Print the compliant skin with the right soft material class; print the load path where fiber reinforcement earns its keep.

What to Watch Next

Watch for follow-on DNGE formulations that Amstad’s team flags — biodegradable or recycled feedstocks that keep mechanics — and for any commercial ink partners that translate microparticle elastomers out of lab printers. Soft robotics and wearable demos that publish cycle-life numbers will show whether the Science Advances toughness and fatigue gains survive real products. Over the next year, shops that already separate “skin” from “structure” in CAD will be ready when a 3D printable elastomer option finally shows up as a purchasable process, not only a paper.

References & Further Reading

1. Baur, E., Kolinski, J., & Amstad, E. (2026). Fatigue-resistant and tough double network granular elastomers. Science Advances.
2. Baur, E., Tiberghien, B., & Amstad, E. (2024). 3D Printing of Double Network Granular Elastomers with Locally Varying Mechanical Properties. Advanced Materials.
3. Resilient polymer brings multipronged toughness to flimsy 3D prints. New Atlas. Retrieved August 12, 2026.