The Future of 3D Printing: How Rapid Liquid Printing is Revolutionizing Manufacturing
- Nathan Griese
- May 19
- 9 min read
Updated: Jul 2
3D printing has long promised efficient, on-demand manufacturing. However, it often struggles with speed, size, and material limitations. Rapid Liquid Printing (RLP) is an emerging technique that addresses these challenges. Developed at MIT’s Self-Assembly Lab, alongside partners like furniture maker Steelcase, RLP allows printers to “draw” entire 3D shapes within a tank of gel.
Instead of layering plastic or resin, RLP injects liquid—often silicone, rubber, or foam—into a specially engineered gel bath. The gel holds each extruded line in place, mimicking a zero-gravity environment, while the material cures. Within minutes, a full-sized part appears, requiring no supports, no gluing, and minimal cleanup. This gel-based process is exponentially faster than traditional methods and employs industry-standard materials like silicones and foams.
How Rapid Liquid Printing Works vs. Conventional 3D Printing
To grasp RLP’s advantages, it’s essential to understand how it contrasts with common 3D printers. Fused Deposition Modeling (FDM) uses a heated nozzle to extrude plastic layer by layer, while SLA printers cure resin with lasers or LEDs, building thin layers. Both methods usually require support structures for overhangs and tend to be slow for larger builds. In contrast, RLP “draws” material in all directions, as the gel bath retains each segment until it hardens.
An RLP machine operates using CAD software to prepare 3D toolpaths, which guide the nozzle through a tank of viscoelastic gel. When the nozzle extrudes liquid into the gel, the material cures instantly. The gel “self-heals” behind the nozzle, closing any path so printed lines stay in place. When printing ends, the entire solid object is raised from the tank and rinsed to remove the gel. There's no need for blasting with heat or UV light, and no post-curing step.
This process fundamentally alters the fabrication landscape. For instance, BMW’s investment arm emphasizes that RLP “eliminates the geometric constraints of traditional layered 3D printing.” Since gravity does not affect uncured material, printing complex, soft shapes—such as long overhangs or lattice structures—becomes feasible without risk of collapse. For example, a recent demo by Steelcase and MIT saw a lattice-topped table printed in roughly half an hour—an endeavor that previously took over 50 hours with standard 3D printing. MIT’s Skylar Tibbits reports parts can now be finished in minutes instead of days due to the rapid curing process facilitated by the gel.
In summary, RLP replaces the slow layer-by-layer approach with a free-form, gravity-free deposition. This gel suspension acts as an invisible scaffold, leading to printed parts that often exhibit better structural integrity compared to those built in unsupported layers. RLP enables the creation of complex shapes considered impossible with conventional methods, as these parts "become ready to use" immediately, without any additional finishing work or wasted support materials.
Advantages: Speed, Scale, Materials, and More
RLP excels in several key areas:
Speed
The first and foremost advantage of RLP is speed. Because the printer does not require time-consuming support structures, RLP operates efficiently at high rates. Reports indicate parts printing in mere minutes—a complex tabletop in approximately 28 minutes, and a component that normally takes about 50 hours on other machines, produced in only 10 minutes. The nozzle functions akin to “opening a faucet”—as soon as the flow begins, the geometry prints rapidly. Studies involving liquid metal RLP have demonstrated at least a tenfold speed increase over other metal additive manufacturing processes, illustrating the technology's time-saving potential.
Large Scale
Next, we have large-scale capabilities. RLP can print very large items because there's no risk of collapse. As noted by BMW, RLP can produce considerable objects, such as a hammock structure, in an eight-foot diameter tank. With a sufficiently expansive gel bath, the potential exists to print an entire piece of furniture or car interior component in one go. This innovative technique circumvents the size limitations of desktop 3D printers and many industrial machines that plateau at the meter scale.
Material Flexibility
The third advantage is material flexibility. RLP utilizes industrial-grade elastomeric materials like silicones, rubbers, and foams, which are difficult to 3D print using traditional methods. In comparison, FDM primarily utilizes PLA or ABS plastics, and SLA resins often lack toughness. RLP can accommodate any curable liquid that solidifies in the gel—making it suitable for materials such as soft rubber and silicone, exhibiting properties akin to molded parts. The print materials typically come from off-the-shelf suppliers, ensuring the final products possess both the softness and durability seen in genuine elastomers. This capability leads to functional prototypes or even end-use products, not just fragile models. Furthermore, RLP allows multi-material blending in real-time, letting printers switch liquids for parts with varying hardness or color gradients.
No Support Structures
One of the most significant advantages of RLP is zero support structures. The suspension gel offers complete safety and reusability, eliminating the need for removing scaffolds. After completing a print, one merely pulls the part out and rinses it off. This negates the need for any cutting away of structural supports or chemical baths. The Rapid Liquid Print company proudly states, “Zero post-production. Zero waste.” This efficiency boosts not just speed but also material usage and labor.
Customization and Design Freedom
Finally, RLP champions customization and design freedom. Because objects are drawn using continuous curves, RLP yields organically flowing, graceful geometries. Designers note the printed lines convey a nearly natural, brushstroke quality. This feature is perfect for creating personalized lattice patterns or sculptural shapes that would normally be complex to mold. The merger of speed and material flexibility enables the kind of on-demand customization that 3D printing is renowned for. For example, one could hastily personalize a lattice cushion to fit a user’s ergonomics.
In essence, RLP combines speed, scale, and strength into a single solution. Steelcase summarizes it well, stating the technique “breaks the three constraints of traditional 3D printing—slow speed, small size, and poor material quality.” Differing from sluggish prototyping machines, RLP can efficiently mass-produce soft parts utilizing familiar materials.
Real-World Applications
Given its diverse benefits, RLP has piqued the interest of various industries, from furniture design to healthcare. Here are some notable examples:
Design & Furniture
Steelcase and designer Christophe Guberan showcased RLP by 3D-printing a customizable table top during Milan Design Week. Their Bassline table design took only about 28 minutes to print. RLP allows for rapid customization of aesthetic elements, such as lattice surfaces, tailored for individual customers. More broadly, RLP was initially presented for interior design and furniture-making, permitting companies to create one-off “3D printed furniture” without molds. This technique is ideal for ergonomic lattice chairs or desks that merge style and function.
Fashion & Consumer Goods
The French fashion brand Coperni made headlines by utilizing RLP to print a silicone handbag, dubbed the “Ariel Swipe” bag, underwater as a unique Disney-themed edition. The founder of Rapid Liquid Print indicates that the company now provides custom 3D-printed items (such as fashion accessories) from its Boston location. Footwear is emerging as another key area; RLP can enable custom insoles or shoe components that are printed quickly in soft foam or rubber. Consequently, designers can create test soles or midsoles in a fraction of the time typically required for tooling.
Automotive
The automotive sector is actively exploring RLP, mainly for soft components. BMW i Ventures led a funding round for the company in 2021, highlighting the ability to produce “large-scale, high-resolution, soft and stretchable products” like seat cushions via RLP. They had even prototyped silicone seat cushions specifically for BMW. More recently, Hyundai introduced adaptive seating at CES 2024 featuring 3D-printed lattice cushions created with RLP. These customized cushions were produced in minutes without the need for molds, tools, or toxic processing steps. RLP is also in the right space to create flexible “bladders” or seals with varying hardness zones, aiding in rapid prototyping for challenging soft parts.
Aerospace & Transportation
RLP’s capacity for creating soft, complex parts is valuable in aircraft interiors and related fields. For instance, custom flexible gaskets and seals relevant to aviation could be made on-demand using RLP. Envision on-demand inflatables, duct linings, or ergonomic panels for aircraft or trains. The process's scalability could not only facilitate large cab component design but potentially create essentials like seat cushioning or panel padding as one piece.
Healthcare & Wearables
Healthcare is a quickly expanding field ripe for RLP innovation. Its capability to produce customizable soft parts positions it perfectly for medical cushions and prosthetics. A remarkable instance comes from the Australian company ProMotion Prosthetics, which uses RLP to print custom silicone liners for prosthetic limbs based directly on patient scans. Previously costing up to $500 and taking weeks to fabricate, RLP can produce these liners in mere minutes for about $250, significantly reducing time and expenses. The method has even successfully produced tailored silicone liners and myoelectric prosthetic fingers (“i-digit”) for amputees. Additional healthcare applications include custom inflatable bladders or soft surgical models. Any medical component requiring patient-specific geometry and elastic materials is a suitable match for RLP.
Art & Fashion Tech
RLP blurs the boundaries between industry and art. Early tests conducted at MIT involved designer Christophe Guberan, and one of his RLP-printed objects was acquired by MoMA, demonstrating its ability to generate iconic, unique items that endure. Fashion runways, furniture fairs, and design museums have featured RLP prints, spotlighting its creative potential that transcends mere functionality.
In summary, RLP is genuinely gaining traction across various sectors, from medical to automotive and beyond. Its appeal extends to tech accelerators and influential publications, with a growing customer base spanning diverse industries. This widespread interest highlights RLP’s versatility: from chair armrests to handbag prototypes, the same gravity-free gel printing technology proves applicable across a multitude of products.
Challenges and Limitations
Despite its promise, RLP is not without challenges. It's vital to recognize its constraints:
Resolution and Surface Finish
RLP tends to trade fine detail for speed and scale. The extruded lines, typically millimeters thick, do not achieve the microscale accuracy of SLA or multi-jet printing processes. The technology sacrifices resolution for its rapid capabilities; RLP parts exhibit a characteristic tubular or striated appearance. While this may be acceptable for applications like cushions, it poses limitations for precision parts.
Material Scope
Currently, RLP excels with soft, curable materials like silicones, urethanes, gels, and waxes that cure at room temperature or via catalysts. However, it cannot print rigid thermoplastics like ABS or PLA without significant modifications. A metal variant of RLP is under investigation at MIT, but standard RLP systems primarily utilize elastomers. The material selection remains narrower than that available with traditional methods. Additionally, RLP produces inherently soft or semi-flexible parts, and it’s not feasible to fabricate something like a rigid plastic gear.
Post-Processing Needs
While the elimination of internal supports enhances the process, it still requires a cleanup step to remove the gel. This gel must be washed off, typically using water, or drained from internal channels. Though BMW claims that rinsing is straightforward, intricate lattices may retain gel in hard-to-reach areas. While this step is minimal compared to traditional support removal, it’s an essential consideration. Moreover, the gel, while reusable, will need reconditioning or filtering after multiple prints, contributing to ongoing costs.
Equipment and Scale
Large-scale RLP demands a spacious gel tank and advanced machinery. Current machines are still in the engineering and demo phases. There’s no commercially available off-the-shelf RLP printer as of yet, complicating the acquisition process. For smaller businesses, the expense and dimensions of RLP equipment may pose initial challenges. At present, RLP services are chiefly delivered by specialized startups or research institutions.
Speed vs. Control
The act of extruding liquid in free space presents challenges. As one researcher explains, controlling liquid flow once it’s molten can be imprecise, making delicate movements more challenging. Ongoing advancements in software algorithms and material viscosities are required to balance speed with precision. Until these technical refinements are completed, creating extremely thin or delicate prints may remain complex.
Limited Mature Ecosystem
Finally, RLP is still in its developmental stage. It lacks the material suppliers, user networks, and well-established design guidelines that traditional 3D printing methods have built over the years. As such, designers and engineers might need to experiment significantly to determine the tolerances and best practices associated with RLP. Surface imperfections and specific geometries could necessitate unique infill patterns within the gel, which require familiarity to navigate.
In conclusion, RLP is not designed to supplant all forms of 3D printing. It excels at creating large, soft, and complex parts—ideal for prototypes and customized products—but won’t eliminate the need for detailed micro-printing or basic rigid components anytime soon. Rather, RLP complements existing technologies, carving out a niche for applications where other methods may struggle.
Looking Ahead
Rapid Liquid Printing is still in its early stages, but it’s evolving rapidly. The spin-off company has recently secured a $7 million Series A funding to develop commercial machines. They are also exploring innovative models like the upcoming “Levity” printer to facilitate RLP’s entry into the market. Major investments from companies like BMW and German entities coupled with press coverage in respected publications indicate a recognized potential within the industry.
Furthermore, ongoing research at MIT continues to push RLP’s boundaries. The Self-Assembly Lab is dedicated to refining the method; exploring new gels, multi-axis robots, and the integration of RLP parts with high-resolution components for a hybrid approach. There are even explorations into RLP-related ideas for bioprinting or composite materials.
As the technology continues to develop, RLP may soon become integrated into traditional production workflows. For instance, furniture makers might utilize it to quickly create tailored soft padding or connectors for chairs. Automotive suppliers could potentially print customized seals or insulation panels as required. Healthcare providers may offer individualized orthopedic or cushioning devices crafted via RLP directly in clinics. Even aerospace manufacturers could benefit by rapidly prototyping cabin interiors or ground support equipment.
For 3D printing enthusiasts and professionals alike, RLP stands out as an exciting tool. It does not replace FDM or SLA; instead, it breaks new ground by merging swift production with genuine industrial-grade materials. As one RLP advocate noted, it “scales without the support struggles,” empowering designers to concentrate on innovation instead of engineering obstacles.
Organizations like Michigan Prototyping Solutions (along with many other prototyping facilities) are keeping a close eye on RLP’s growth. As customization and speed become paramount, gravity-free 3D printing could unlock capabilities previously only dreamed of. Transitioning from lab demonstrations to actual production, RLP may soon be among the “conversational tools”—to borrow a phrase—that redefine the creation of products, apparel, and parts in the future.
Sources: The above draws on MIT Self-Assembly Lab descriptions and publications selfassemblylab.mit.edu, industry analyses 3dprintingindustry.com, and news articles covering RLP developments venturebeat.com.