ItInsightsWorld Research Brief: 3D Printing Advances in X-Hinges, Nuclear Formwork, Liquid-Metal Skins, and Color Routers

With Formnext only a few weeks away, ItInsightsWorld groups four additive manufacturing updates around one theme: 3D printing is extending into sensing, infrastructure, soft-machine function, and imaging optics.

This briefing follows the research institutions and application outcomes rather than the event calendar.

X-Hinges Places Sensors Where Printed Motion Happens

In the MIT & TJU work, the shift is mainly software: engineers at MIT and Tianjin University (TJU) in China developed “X-Hinges,” a tool that automatically places sensors into 3D models at relevant points of articulation.

When supplied with a robotic-hand model, X-Hinges places sensors at the joints to capture motion data, allowing the printed device to respond more dynamically to users’ intentions.

“It’s kind of like adding a conscious element to everyday objects,” said Jiaji Li, MIT electrical engineering and computer science (EECS) postdoc. “What you get is objects that better understand how they’re being used and have more ways to respond. In the same way an AI agent is programmed to make certain decisions based on our instructions, these creations have built-in sensing to adaptively react to human touch.”

As a proof of concept, Li and his colleagues used X-Hinges to build a teaching glove: it adjusts to a user’s hand size, records finger-joint bending through sensors, and relays that data to a humanoid robot hand for imitation.

“Most methods only allow for one axis of motion, often due to signal interference. X-Hinges enables your 3D printed item to move from three angles,” said lead author Xiang Chang. “Ultimately, you get a design with the intended movement you want. It also records motion data in each of those areas at the same time, making the device responsive to different kinds of interactions.”

The open-access paper is posted on arXiv, and the work is scheduled for presentation at the ACM Symposium on User Interface Software and Technology (UIST) next month.

ORNL-Linked Nuclear Forms Compress Build Time

“Advanced Composite Formwork for Accelerated High-Precision Nuclear Infrastructure,” a collaborative project involving Oak Ridge National Laboratory (ORNL), applies 3D printed composite forms to nuclear construction, where Oak Ridge is trying to reduce a known schedule bottleneck.

The project partners joined ORNL’s Manufacturing Demonstration Facility and included:

• Kairos Power,
• the University of Maine’s Advanced Structures and Composites Center,
• Barnard Construction,
• Airtech Advanced Materials Group,
• JuggerBot 3D,
• Additive Engineering Solutions,
• Haddy,
• and Tru-Design.

In a matter of days, Kairos Power and Barnard Construction teams completed the Janus cast-in-place concrete demonstration. IMAGE: Kairos Power

The group developed a digital manufacturing process for fiber-reinforced composite forms. They can be designed, 3D printed, and delivered in roughly two weeks instead of the six months usually required for conventional steel molds; the forms also achieved one-sixteenth-inch precision on critical surfaces while withstanding the substantial pressure exerted by the concrete they were built to shape.

“Accelerating advanced nuclear deployment requires rethinking how we build, not just how we design reactors,” said Ahmed Arabi Hassen, group leader of composites innovation at ORNL. “Conventional formwork is costly, labor-intensive and too slow to support the pace and scale of future nuclear construction. Through large-scale additive manufacturing and strong industry partnerships, we are transforming this bottleneck into an opportunity to build faster, smarter and more affordably.”

The project recently received the 2026 CAMX Combined Strength Award.

Liquid-Metal Skins Make Soft Robots Conductor-Friendly

engineering.com has covered 3D printed soft robots for years, yet combining pliable, synthetic bodies with metallic pathways that fracture under repeated strain remains difficult. A research team from Sichuan University in China addresses that problem by combining stereolithography (SLA) with laser-induced selective metallization.

The team exploits the selective adhesion of a magnetic liquid-metal slurry made from Galinstan and iron particles to copper patterns produced by laser-induced selective metallization. This lets them fabricate flexible devices that crawl on flat surfaces and slopes, move across water, shield electromagnetic interference, and restore cut conductive traces with magnetic assistance.

The technique incorporates nanoscopic zinc oxide particles into a photosensitive resin. By selectively activating designated regions on the printed surface with the laser, researchers guide electroless copper deposition to create precise metallic patterns that serve as an interfacial layer for the magnetic liquid metal.

The printed liquid-metal traces measure 58.6 μm across and remain electrically isolated with gaps as narrow as 40.23 μm.

On the abdomen of a soft, 3D-printed caterpillar, a magnetic liquid-metal pattern responds to changes in an external magnetic field, driving alternating extension and contraction that enables the robot to climb a slope. IMAGE: Siying Li, Pengan Luo, Hao Lu, Haoran Xu, Feifan Yu, Jin Feng and Tao Zhou

When the team patterned the magnetic slurry only along the abdomen of a soft, 3D-printed caterpillar, fluctuating magnetic fields made the robot rhythmically buckle and extend; it moved forward 3.5 cm in 15 seconds and climbed a 30° ramp.

The researchers caution that they still need to verify that trace metal ions do not leach into human tissue during prolonged contact with acidic sweat or physiological fluids. They also need to develop thin, breathable polymer coatings that protect exposed liquid traces from physical friction without compromising flexibility.

The paper is available open-access in the International Journal of Extreme Manufacturing.

SUTD Color Routers Direct Light for Low-Light Sensors

When digital cameras are used for low-light photography, light is often lost as it passes through color filters before reaching the sensors. In dim conditions, that produces images with more noise, longer exposure, and increased motion blur. Researchers at Singapore University of Technology and Design (SUTD) in Singapore created a color router designed to minimize this issue by “steering” light to sensors rather than filtering it.

“A Bayer filter separates colors by letting one color through and absorbing the others,” explained professor and lead researcher, Joel Yang from SUTD. “A color router instead steers those colors towards the corresponding sensing regions, allowing three times more of the incoming light to be used.”

Earlier color routers relied on high-refractive-index materials such as titanium dioxide or gallium nitride. Those materials bend light strongly, but they demand precise, multi-step fabrication. The SUTD team instead turned to low-refractive-index materials: ordinary polymers and glasses, which are less expensive and easier to scale but have been overlooked because of their weaker interaction with light.

“Building on our experience with 3D-printed polymer optics, we wanted to explore whether carefully optimized geometry could overcome that limitation,” said lead author and SUTD PhD candidate, Pan Cheng-Feng.

Using 3D printing’s unique geometric flexibility to overcome physical limitations, the team designed a color router in which each unit cell contains four cylindrical nanopillars. These pillars are printed to precise heights and widths using two-photon polymerization (2PP). Instead of acting as individual color filters, the nanoscopic pillars scatter light so that it interferes collectively, steering red, green, and blue wavelengths toward their target destinations.

Low-refractive-index color routers for image sensors are shown: (a,b) schematics comparing a conventional Bayer-filter sensor with a color-router-based sensor; (c) refractive index and chromatic dispersion comparison for representative optical materials, highlighting low-index, low-dispersion materials; (d) scanning electron micrographs of fabricated polymer nanopillars and periodic array; (e) optical image of routed color pattern, with one RGGB unit cell outlined. IMAGE: SUTD

“The four pillars act as a coordinated optical system,” said Pan. “A pillar positioned beneath the red sensing region is not simply an independent ‘red pillar’. In our design, the desired routing emerges from the collective response of the complete arrangement.”

The researchers report that images captured through their router showed improved color fidelity with a third of the exposure time compared to a standard filter-based sensor. Simulations indicated a routing efficiency of almost 90 percent across the visible spectrum, compared to 20-35 percent in an off-the-shelf filter. When printed as arrays of 250,000 unit cells across a one-millimeter square, the routers achieved approximately 70 percent efficiency, a drop the team attributes to fabrication-induced deviations from the ideal design.

For the next phase, the SUTD researchers plan to combine their color router with an image sensor and test how optical gains translate into improvements in exposure time, noise, and color accuracy. They also aim to reduce leakage between color channels, improve performance for light arriving at different angles, and demonstrate repeatable replication.

The study appears in the journal Nature Communications.

For ItInsightsWorld readers, the common thread is not a single printer or material, but the way 3D printing moves value into sensors, nuclear infrastructure, soft-robot conductors, and imaging optics.