A new review by researchers from the Beijing University of Posts and Telecommunications, CETC 54 (54th Research Institute of Electronics Technology Group Corporation), Sun Yat-sen University, Shenzhen University, and the University of Electronic Science and Technology of China surveys the latest developments in 3D printing for microelectronic and microfluidic applications. The paper released on Springer Nature Link highlights how additive manufacturing methods have reached sub-micron precision, allowing the production of devices previously limited to traditional cleanroom fabrication. High-resolution techniques like two-photon polymerization (2PP), electrohydrodynamic jet printing, and computed axial lithography (CAL) are now being used to create structures with feature sizes down to 100 nanometers. These capabilities have broad implications for biomedical sensors, flexible electronics, and microfluidic systems used in diagnostics and environmental monitoring. Overview of 3D printing applications for microelectronic and microfluidic device fabrication. Image via Springer Nature. Classification of High-Precision Additive Processes Seven categories of additive manufacturing, as defined by the American Society for Testing and Materials (ASTM) serve as the foundation for modern 3D printing workflows: binder jetting, directed energy deposition (DED), material extrusion (MEX), material jetting, powder bed fusion (PBF), sheet lamination (SHL), and vat photopolymerization (VP). Among these, 2PP provides the finest resolution, enabling the fabrication of nanoscale features for optical communication components and MEMS support structures. Inkjet-based material jetting and direct ink writing (DIW) allow patterned deposition of conductive or biological materials, including stretchable gels and ionic polymers. Binder jetting, which operates by spraying adhesives onto powdered substrates, is particularly suited for large-volume structures using metals or ceramics with minimal thermal stress. Fused deposition modeling, a form of material extrusion, continues to be widely used for its low cost and compatibility with thermoplastics. Although limited in resolution, it remains practical for building mechanical supports or sacrificial molds in soft lithography. Various micro-scale 3D printing strategies. Image via Springer Nature. 3D Printing in Microelectronics, MEMS, and Sensing Additive manufacturing is now routinely used to fabricate microsensors, microelectromechanical system (MEMS) actuators, and flexible electronics. Compared to traditional lithographic processes, 3D printing reduces material waste and bypasses the need for masks or etching steps. In one example cited by the review, flexible multi-directional sensors were printed directly onto skin-like substrates using a customized FDM platform. Another case involved a cantilever support for a micro-accelerometer produced via 2PP and coated with conductive materials through evaporation. These examples show how additive techniques can fabricate both support and functional layers with high geometric complexity. MEMS actuators fabricated with additive methods often combine printed scaffolds with conventional micromachining. A 2PP-printed spiral structure was used to house liquid metal in an electrothermal actuator. Separately, FDM was used to print a MEMS switch, combining conductive PLA and polyvinyl alcohol as the sacrificial layer. However, achieving the mechanical precision needed for switching elements remains a barrier for fully integrated use. 3D printing material and preparation methods. Image via Springer Nature. Development of Functional Inks and Composite Materials Microelectronic applications depend on the availability of printable materials with specific electrical, mechanical, or chemical properties. MXene-based conductive inks, metal particle suspensions, and piezoelectric composites are being optimized for use in DIW, inkjet, and light-curing platforms. Researchers have fabricated planar asymmetric micro-supercapacitors using ink composed of nickel sulfide on nitrogen-doped MXene. These devices demonstrate increased voltage windows (up to 1.5 V) and volumetric capacitance, meeting the demands of compact power systems. Other work involves composite hydrogels with ionic conductivity and high tensile stretch, used in flexible biosensing applications. PEDOT:PSS, a common conductive polymer, has been formulated into a high-resolution ink using lyophilization and re-dispersion in photocurable matrices. These formulations are used to create electrode arrays for neural probes and flexible circuits. Multiphoton lithography has also been applied to print complex 3D structures from organic semiconductor resins. Bioelectronic applications are driving the need for biocompatible inks that can perform reliably in wet and dynamic environments. One group incorporated graphene nanoplatelets and carbon nanotubes into ink for multi-jet fusion, producing pressure sensors with high mechanical durability and signal sensitivity. 3D printed electronics achieved through the integration of active initiators into printing materials. Image via Springer Nature. Microfluidic Devices Fabricated via Direct and Indirect Methods Microfluidic systems have traditionally relied on soft lithography techniques using polydimethylsiloxane (PDMS). Additive manufacturing now offers alternatives through both direct printing of fluidic chips and indirect fabrication using 3D printed molds. Direct fabrication using SLA, DLP, or inkjet-based systems allows the rapid prototyping of chips with integrated reservoirs and channels. However, achieving sub-100 µm channels requires careful calibration. One group demonstrated channels as small as 18 µm × 20 µm using a customized DLP printer. Indirect fabrication relies on printing sacrificial or reusable molds, followed by casting and demolding. PLA, ABS, and resin-based molds are commonly used, depending on whether water-soluble or solvent-dissolvable materials are preferred. These techniques are compatible with PDMS and reduce reliance on photolithography equipment. Surface roughness and optical transparency remain concerns. FDM-printed molds often introduce layer artifacts, while uncured resin in SLA methods can leach toxins or inhibit PDMS curing. Some teams address these issues by polishing surfaces post-print or chemically treating molds to improve release characteristics. Integration and Future Directions for Microdevices 3D printed microfluidic devices in biology and chemistry.Image via Springer Nature. 3D printing is increasingly enabling the integration of structural, electrical, and sensing components into single build processes. Multi-material printers are beginning to produce substrates, conductive paths, and dielectric layers in tandem, although component embedding still requires manual intervention. Applications in wearable electronics, flexible sensors, and soft robotics continue to expand. Stretchable conductors printed onto elastomeric backings are being used to simulate mechanoreceptors and thermoreceptors for electronic skin systems. Piezoelectric materials such as BaTiO₃-PVDF composites are under investigation for printed actuators and energy harvesters. MEMS fabrication remains constrained by the mechanical limitations of printable materials. Silicon continues to dominate high-performance actuators due to its stiffness and precision. Additive methods are currently better suited for producing packaging, connectors, and sacrificial scaffolds within MEMS systems. Multi-photon and light-assisted processes are being explored for producing active devices like microcapacitors and accelerometers. Recent work demonstrated the use of 2PP to fabricate nitrogen-vacancy center–based quantum sensors, capable of detecting thermal and magnetic fluctuations in microscopic environments. As materials, resolution, and system integration improve, 3D printing is poised to shift from peripheral use to a central role in microsystem design and production.  3D printing micro-nano devices. Image via Springer Nature. Ready to discover who won the 20243D Printing Industry Awards? Subscribe to the 3D Printing Industry newsletter to stay updated with the latest news and insights. Take the 3DPI Reader Survey — shape the future of AM reporting in under 5 minutes. Featured image shows an Overview of 3D printing applications for microelectronic and microfluidic device fabrication. Image via Springer Nature. Anyer Tenorio Lara Anyer Tenorio Lara is an emerging tech journalist passionate about uncovering the latest advances in technology and innovation. With a sharp eye for detail and a talent for storytelling, Anyer has quickly made a name for himself in the tech community. Anyer's articles aim to make complex subjects accessible and engaging for a broad audience. In addition to his writing, Anyer enjoys participating in industry events and discussions, eager to learn and share knowledge in the dynamic world of technology.

Wētā Digital – now part of Unity – developed many of the tools and solutions used to bring the world of Avatar: The Way of Water to life. Here, we take a look at the CGI technology behind the water. If you’re interested in being among the first to access some of the tools used in the film, you can register for the Unity Wētā Tools beta through our website.James Cameron is no stranger to working with water. Titanic aside, in 2012 he made a record-breaking solo dive, piloting a submarine to the bottom of the Mariana Trench in the Pacific Ocean: Earth’s lowest point at nearly 11 kilometers deep. As he said in the resulting 2014 documentary, Deepsea Challenge, “Down here you feel the power of nature’s imagination, which is so much greater than our own.”It must have been truly remarkable, then, seeing as the world of Pandora and its stunning visuals ultimately came from Cameron’s own imagination.Translating Cameron’s vision, which for the sequel included the new reef village of the aquatic Metkayina clan, required extensive use of visual effects – especially for the dominant water setting.The tools and solutions used to create the film’s VFX – including the award-winning water effects – were developed by Wētā Digital, now a division of Unity.To ensure that the interactions between the characters and water elements were as realistic as possible, a team of experts, including Unity and Wētā’s water simulation VFX specialists Alexey Stomakhin, Steve Lesser, Joel Wretborn, and Sean Flynn, were brought together to form the “Water Taskforce”. This team’s water toolset was recently recognized with a win at the Visual Effects Society (VES) Awards, with the Emerging Technology Award.Extreme attention to detail saw the taskforce conduct extensive research and experimentation in collaboration with New Zealand’s National Institute of Water and Atmospheric Research (NIWA) to find the best approach to creating CGI water. This included taking into account the effects of tides, wind, and the sea floor on aquatic environments.Avatar: The Way of Water required water effects for 2,225 shots, some taking up to eight days of simulation to achieve the high resolution needed.There were also numerous scenes where water interacted with over 50 creatures in a single shot. This presented the challenge of needing simulations to be accurate at scale, from large domains for bigger creatures, to submillimeter resolution for thin film on skin.As it was not computationally feasible to create a single-representation water system, the toolset was developed with a number of distinct solvers to keep compute times to a minimum.“The Loki water state machine was crucial for delivering the sheer volume of large-scale water shots in this movie. In a typical VFX-heavy movie, water shots of this complexity are few and far between and require many iterations and passes from very experienced artists. In contrast, our state machine approach was able to deliver great results after just a single pass, even by artists who had just entered the industry.” – Sean Flynn, simulation lead, Unity x Wētā DigitalA majority of the water tools developed by the team sit within Wētā’s proprietary simulation framework, Loki. This piece of tech includes solvers for multiple water states, including procedural water waves, bulk water, spray, mist, hero bubbles, diffuse bubbles, foam, capillary surface waves, thin film, and residual wetness.State machineMany of these solvers sit within the Loki state machine – an airborne spray system. The water states are coupled with the surrounding air, with transitions between states handled in a mass- and momentum-conserving way.Rather than a one-size-fits-all approach, the Loki state machine allows multiple solvers to run in tandem. Each solver is optimized for the level of detail required by its respective state, such as bulk water, spray, and mist. This helps keep large-scale water simulations efficient while still capturing the very fine droplet interactions required by spray and mist.All of the states including the surrounding air are completed in a single simulation pass. As all solvers are computed with proper physical interactions between them, this is what helped to create such natural and realistic water interaction throughout the film.During SIGGRAPH 2019, a practical approach for modeling close-up water interaction with characters was presented, with a focus on high-fidelity surface tension and adhesion effects as water moves over and drips from skin. Using a scene from Alita: Battle Angel (a screenplay also written by Cameron), the team showed how this method allowed for a resolution of effects that was performant enough – on the scale of a fraction of a millimeter – to cover a whole character with a layer of water.The approach was to adapt an existing particle-in-cell (FLIP/APIC) solver to capture small-scale water-solid interaction dynamics. This technique was then advanced during the production of Avatar: The Way of Water to handle any sequence that involved characters emerging from water.“This was not a cheap solution, as we had to simulate water dynamics at sub-millimeter scales. The results would often take days to compute. We had to ensure our solver was scalable, robust and reliable enough to produce physically plausible visuals out of the box, with minimal tuning required from artists.” – Alexey Stomakhin, principal research engineer, Unity x Wētā DigitalTo achieve believable dynamics in underwater scenarios – for example, when characters breathe underwater in Avatar: The Way of Water – the approach to underwater bubbles was to simulate them together with a narrow band of water around the region of interest. The bubbles themselves would be represented in two parts: a hero and diffuse counterpart.The hero counterpart captures bigger bubbles with more explosive and turbulent behaviors. It utilizes an incompressible two-phase Navier-Stokes solve on a Eulerian grid, with the air phase represented by FLIP/APIC particles to facilitate volume conservation and accurate interface tracking.The diffuse counterpart captures the motion of smaller bubbles below the resolution of the Eulerian grid. The team has developed a novel scheme for coupling diffuse bubble particles with bulk fluid that could also be applied to other submerged, porous objects such as sand, hair, and cloth.To enhance the visual detail of a water surface simulation, the team from Wētā Digital and IST Austria developed a method of post-processing that took a simulation as an input, and increased its apparent resolution by simulating detailed Lagrangian water waves on top of it.Linear water wave theory was extended to work in non-planar domains with Lagrangian wave packets attached to spline curves that would evolve over the bulk fluid surface. This method produces high-frequency ripples with dispersive wave-live behaviors, customized to the underlying fluid simulation.A technique was developed for the realistic movement of underwater bubbles – created by movement in the water – reaching the water surface and converting into foam. This was important for nearly all of the water scenes in Avatar: The Way of Water.Grid-based Navier-Stokes simulators – usually reserved for capturing large-scale motion such as bulk fluid – are inherently limited by their grid resolution, making this method impractical for small-scale phenomena like spray and mist from breaking waves. These whitewater effects are usually simulated as independent Lagrangian particles.“One key aspect of our whitewater method is the interaction of two solvers: a grid-based fluid solver coupled with bubbles, and a SPH solver for foam constrained to the water surface. The declarative solver framework in Loki is what makes building and supporting these complex systems possible in production without having to develop new solvers from scratch.” – Joel Wretborn, senior research engineer, Unity x Wētā DigitalThe key aspect most of the existing solvers neglect are the collective effects: groups of bubbles rise faster than single bubbles due to their combined buoyancy, and the collection of many bubbles can have a significant impact on the motion of the water.The new technique addresses this limitation by simulating bubbles two-way coupled with the surrounding fluid. This effectively captures collective bubble effects, and creates a more connected look between bubbles and the motion of the fluid. As bubbles reach the surface they transition into "wet" foam particles constrained to the water surface, discretized with smoothed particle hydrodynamics (SPH). In the end this created believable whitewater dynamics in both close-up and large ocean shots.The simulation technology used by the Water Taskforce was created by present and former colleagues at Wētā Digital, as well as friends from Wētā FX and academic institutions, including: Alexey Stomakhin, Joel Wretborn, Kevin Blom, Gilles Daviet, Steve Lesser, John Edholm, Noh-Hoon Lee, Eston Schweickart, Xiao Zhai, Sean Flynn, Andrew Moffat, Gary Boyle, Tomas Skrivan, Andreas Soderstron, John Johansson, Christoph Sprenger, Ken Museth, and Chris Wojtan. Learn more about Unity Wētā Tools beta.

During an excavation, amidst the Patagonian winds and hard rock, a fossil began to turn green. It was an unexpected reaction: the adhesive applied to protect the bones, fragile after millions of years beneath the ice, had interacted with plant matter trapped in the rock’s cracks. This greenish hue earned the fossil the nickname Fiona, like the ogre from Shrek.But Fionais much more than a ogre-themed name. It is the first complete ichthyosaur ever excavated in Chile and, even more remarkably, the only known pregnant female from the Hauterivian — a stage of the Early Cretaceous dating back 131 million years. Her skeleton, discovered at the edge of the Tyndall Glacier in Torres del Paine National Park — an area increasingly exposed by glacial retreat — belongs to the species Myobradypterygius hauthali, originally described in Argentina from fragmentary remains.The discovery, led by Judith Pardo-Pérez, a researcher at the University of Magallanes and the Cabo de Hornos International Center (CHIC), and published in the Journal of Vertebrate Paleontology, offers an unprecedented glimpse into ancient marine life — from how these majestic reptiles reproduced to how they adapted to oceans vastly different from those of today.An Ichthyosaur Maternity Ward in Patagonia(Image Courtesy of Irene Viscor)So far, 88 ichthyosaurs have been found on the Tyndall Glacier. Most of them are adults and newborns. Two key facts stand out: food was abundant, and no other predators were competing with them.Fiona, who measures nearly 13 feet long, is still encased in five blocks of rock. Despite the challenge, she was transported to a local clinic, where CT scans allowed researchers to study her skull and body. Her species was identified thanks to one of her fins. “There’s no other like it in the world,” says Pardo-Pérez. The limbs were remarkably elongated, suggesting this animal was built for long-distance swimming.Inside her, there were more surprises. One of them was her stomach contents, which revealed what may have been her last meal: tiny fish vertebrae. But the most striking find was a fetus, about 20 inches long, already in a position to be born.“We believe these animals came to Magallanes — the southern tip of Chilean Patagonia — from time to time to give birth, because it was a safe refuge,” Pardo-Pérez says. “We don't know how long they stayed, but we do know that mortality was high during the first few days of life.”One of the big unanswered questions is where they went next, as there are no records of Myobradypterygius hauthali, apart from a piece of fin found in Argentina. The most abundant remains come from southern Germany, but those date back to the Jurassic period, meaning they’re older.Palaeontologist Erin Maxwell suggests, “In many modern ecosystems, species migrate to higher latitudes during the summer to take advantage of seasonally abundant resources and then move to lower latitudes in winter to avoid harsh conditions,” she explains. “We believe Mesozoic marine reptiles may have followed similar seasonal patterns.”Sea Dragon GraveyardThe environment where Fiona was discovered — dubbed the "sea dragon graveyard" — also has much to reveal.According to geologist Matthew Malkowski of the University of Texas at Austin, the Hauterivian age is particularly intriguing because it coincided with major planetary changes: the breakup of continents, intense volcanic episodes, and phenomena known as "oceanic anoxic events," during which vast areas of the ocean were depleted of dissolved oxygen for hundreds of thousands of years.One such poorly understood event, the Pharaonic Anoxic Event, occurred around 131 million years ago, near the end of the Hauterivian, and still raises questions about its true impact on marine life. “We don't have a firm grasp of how significant these events were for marine vertebrates, and geological records like that of the Tyndall Glacier allow us to explore the relationship between life, the environment, and Earth’s past conditions,” Malkowski notes.Evolution of IchthyosaursReconstruction of Fiona. (Image Courtesy of Mauricio Álvarez)Don't be misled by their body shape. “Ichthyosaurs are not related to dolphins,” clarifies Pardo-Pérez. Although their hydrodynamic silhouettes may look nearly identical, the former were marine reptiles, while the latter are mammals. This resemblance results from a phenomenon known as convergent evolution: when species from different lineages develop similar anatomical features to adapt to the same environment.Ichthyosaurs evolved from terrestrial reptiles that, in response to ecological and climatic changes, began spending more time in the water until they fully adapted to a marine lifestyle. However, they retained traces of their land-dwelling ancestry, such as a pair of hind flippers — absent in dolphins — passed down from their walking forebears. They lived and thrived in prehistoric oceans for about 180 million years, giving them ample time to refine a highly specialized body: their forelimbs and hindlimbs transformed into flippers; they developed a crescent-shaped tail for propulsion, a dorsal fin for stability, and a streamlined body to reduce drag in the water. Remarkably, like whales and dolphins, “ichthyosaurs had a thick layer of blubber as insulation to maintain a higher body temperature than the surrounding seawater and gave birth to live young, which meant they didn’t need to leave the water to reproduce,” explains Maxwell.Whales and dolphins also descend from land-dwelling ancestors, but their transition happened over a comparatively short evolutionary timespan, especially when measured against the long reign of the ichthyosaurs. “Their evolution hasn't had as much time as that of ichthyosaurs,” notes Pardo-Pérez. “And yet, they look so similar. That’s the wonderful thing about evolution.”Read More: Did a Swimming Reptile Predate the Dinosaurs?Fossils on the Verge of DisappearanceOne of the key factors behind the remarkable preservation of the fossils found in the Tyndall Glacier is the way they were buried. According to Malkowski, Fiona and her contemporaries were either trapped or swiftly covered by underwater landslides and turbidity currents — geological processes that led to their sudden entombment.But the good fortune that protected them for millions of years may now be running out. As the glacier retreats, exposing fossils that were once unreachable, those same remains are now vulnerable to wind, rain, and freeze-thaw cycles, which crack the surrounding rock. As vegetation takes hold, roots accelerate erosion and eventually conceal the fossils once again.“While climate change has allowed these fossils to be studied, continued warming will also eventually lead to their loss,” Maxwell warns. In Fiona’s story, scientists find not only a record of ancient life, but also a warning etched in stone and bone: what time reveals, climate can reclaim.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:María de los Ángeles Orfila is a science journalist based in Montevideo, Uruguay, focusing on long-form storytelling. Her work has appeared in Discover Magazine, Science, National Geographic, among other outlets, and in leading Uruguayan publications such as El País and El Observador. She was a fellow in the 2023 Sharon Dunwoody Mentoring Program by The Open Notebook and often explores the intersections of science, culture, and Latin American identity.