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Israel Institute of Technology

Multi-Material 3D Printing Enables Functional Testing for Heroic Robots

“The wide range of the Objet350 Connex Digital Materials enabled us to produce a fully functional hyper-redundant robot for real world physical testing in a matter of days

— Alon WolfTechnion

Israel Institute of Technology

At a Glance


  • Creating structurally complex parts that can withstand real world physical testing and functional use
  • Finding a 3D printing system prints diverse materials in one build
  • Create models quickly and cost effectively


  • The Objet350 Connex 3D Printer


  • Can now create accurate, structurally complex models that can withstand impact and absorb shocks
  • Able to create intricate overmolding structures that work
  • Reduced response time for modifications and changes
  • Achieved desired results in the shortest time with the lowest costs

Rigid and flexible materials in one build to create this housing with a protective coating.

Technion 3D Printed Part

Errors and potential design changes can be identified much earlier in the design process.

Robotic component

Errors and potential design changes can be identified much earlier in the design process.

To the rescue

Beyond CAD

At the Technion, Israel Institute of Technology’s biorobotics and biomechanics lab (BRML) research in kinematics and mechanism design is motivated by the belief that many designers are overly dependent on computer-aided design tools and software results. In contrast, BRML focuses on asking meaningful questions and searching for fundamental understanding through real-world testing. Fascinated by the depth and complexity of analyzing and synthesizing bodies in motion, Dr. Alon Wolf and his team use kinematics tools, such as 3D models, to provide insight into their modes of operation.

Founded by Wolf, BRML develops mechanical structures, control strategies and motion planning for hyper-redundant mechanisms. A redundant robot has at least one extra degree of freedom (DOF) than required, to compensate for simple constraints, e.g., using an elbow up versus an elbow down configuration, to reach a target position. Hyper-redundant robots have many more DOF than required. This lets them handle more constraints, in highly convoluted volumes, while performing diverse tasks. BRML uses an Objet350 Connex 3D Printer to create robust, fully functional models that investigate the kinematics, design criteria and control strategy for these complex mechanisms. They focus on hyper-redundant robots which are either mounted to a fixed base (like an elephant trunk), or are unconstrained (like a snake). PolyJet, the technology that drives Objet 3D Printers, is the only 3D printing method that can build multiple-material models in a single job.

The lab focuses on developing robots that can directly contribute to science and society. For example, its work in medical devices enables procedures that were impossible before. And its work in search and rescue robotics means faster detection of survivors with less risk of injury for rescuers.

Tough Requirements

After a comprehensive study of the available 3D printing technologies around the world, BRML found the Objet350 Connex 3D Printer optimal for its broad range of research fields. This is due to the 3D printer’s high resolution, smooth surfaces and ability to combine wide range of mechanical properties, such as tensile, flexural and impact strength, in one build. These multi-material models with targeted strengths proved durable enough for BRML’s demanding functional tests.

PolyJet 3D Printing lets BRML print complex structures in one build. For example, the lab needed a stiff casing with a protective coating, so it used a rigid photopolymer for the casing and Rubber-like material for the coating, to provide shock absorption, impact resistance and the required dynamic friction coefficient. The team’s extensive research confirmed that PolyJet 3D Printing is the only method that can deliver this combination of physical properties in a single build.

Better Results, Faster and at Less Cost

According to Oded Salomon, biorobotics research engineer it is important to “emphasize the enormous upgrade in the way we are conducting our research today as compared to a year ago. The Objet Connex 3D Printing System allows us to create real functional models, for real world physical testing, in a matter of days. This allows us to achieve the desired results in the shortest time with the lowest costs.”

3D printing has not just saved time, it’s allowed the team to print models that simply couldn’t have existed before. Designing for manufacturing using Objet 3D Printing technology is totally different than conventional CNC and other technologies, as it allows complex, over-molding models that cannot be manufactured using other technologies. Salomon explains, “Designing using CAD is nice but there is really no comparison to a handheld from an Objet Connex functional model.”

Today BRML can involve more complex construction considerations to their design -- a result of having Objet’s,“amazing matrix technology.”

Objet 3D technology compresses the amount of time it takes for BRML to get to the final product, which in robotics research means many more concepts can be checked and compared in considerably less time. This creates better models faster, which in turn saves costs. As a result, BRML is now able to have the chosen model design, fine-tuned in a shorter period of time, creating better overall results.

“Placing the Objet Connex inside a regular office is even more appealing and gives a stronger meaning to the words ‘compression of time and accessibility,’” says Dr. Wolf. The ability to print accurate models quickly in-house means Wolf’s team can test more concepts and identify costly mistakes earlier in the design process — crucial when you’re creating something as complex as a robotic snake with many vertebrae. The result is better finished products, created faster and at less cost. Office-friendly PolyJet technology means BRML’s 3D printer is in an accessible area, making it useful across disciplines. The systems serves all researchers in mechanical engineering at Technion, and has also proven useful in aeronautics research and for student projects and instructional applications.

The individual scientists have also won thanks to their use of Objet models. Their research has been greatly promoted, and some of their discoveries have been patented thanks to the working prototypes that were manufactured using this technology. One key factor in helping this happen is having the Objet Connex in-house, where confidentiality prevents further discussion.

“This kind of technology is a must when it comes to robotics research,” says Wolf. “Nothing compares to the ability to hold your last-night crazy idea in your hands the very next morning.”

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