Düsseldorf, June 19, 2025 – Envalior, SENTImotion and Frencken Group have developed a new gearbox concept for robot arms based on advanced engineering plastic. Unlike previous designs based on metal or plastic, it enables the entry into the cost-effective large-scale production of lightweight and energy-efficient robots. The development partners are presenting the new concept to the general public for the first time at the automatica robotics trade fair in Munich, Germany.
The concept named SMFdrives is based on components made of Stanyl® PA46 from Envalior. Thanks to polyamide 46 and a weight-optimized design, the gearboxes weigh approximately half as much as their metal counterparts. Production costs are around 50% lower because the gear parts can be manufactured economically in large quantities using precision injection molding. The gearboxes are highly durable and very wear-resistant. They meet all the mechanical requirements for safe and reliable operation over the entire service life of the robots.
The hidden breakthrough driving the robotics revolution
The combination of artificial intelligence (AI) and robotics is causing a stir around the world. However, one thing is often overlooked: Even the most intelligent robots still have to rely on physical hardware - especially actuators. Until now, the high overall cost of robotic systems has been a major hurdle to their widespread acceptance, in addition to their weight. The new ultra-light plastic gears have the potential to change this. They lower the cost of these robots towards the 10,000 dollar mark, opening the door to the mass market. “This fusion of AI with the highest level of engineering marks the “ChatGPT moment” in robotics - a leap towards physical AI,” explained Dr. Tamim Sidiki, Segment Innovation Manager Mobility at Envalior.
Go-ahead for major projects with robot manufacturers
“SMFdrives is ready for series production. The development partners now want to enter into large-scale projects together with robot manufacturers and their suppliers. The initial goal is the mass production of humanoid and service robots for domestic use, retail, department store logistics and the patient care sector, for example. We are also working on optimizing the new generation of gearboxes for demanding industrial robotics applications,” explained Steffen Breuninger, Managing Director of SENTImotion GmbH, an engineering service provider that designs highly efficient and universal drive technology with maximum power density.
Reliable global supply for robot manufacturers
Frencken Group, a global provider of integrated technology solutions for the automotive, healthcare, industrial and aerospace sectors, among others, is acting as the industrial partner for the mass production of the gearboxes and associated plastic parts in the joint project.
“We have the processing expertise to precisely manufacture the carefully designed gear components, which have a high level of detail and their own special gearing, with tight tolerances in large quantities by injection molding. With our experience in automation technology, we can produce the gears efficiently and reliably supply robot manufacturers over short distances thanks to our global footprint,” said Ron Borger, Managing Director of the Frencken IMS division for the region ESEA.
Plastic gearboxes do not require any braking systems
A further advantage of SMFdrives is that no separate braking systems are required in the gearboxes to prevent unwanted backdrive. This is due to an intrinsic backdrive lock that is integrated into the gearbox design. Thus, the weight of the gearboxes and the total number of parts required for their assembly are reduced. The elimination of the brake systems also has a noticeable effect on the overall costs for the robots and their weight. Another advantage of the concept is that the plastic gearboxes are compatible with the form factors of conventional robot gearboxes. They can be easily integrated into the installation spaces of existing robot concepts that are intended for metal gears.
High torque densities and high reduction ratios
Envalior, a leading supplier of high-performance thermoplastics, used its extensive technical expertise in materials, plastic gear design and CAE simulations to refine the design of the gearbox components. The focus was on manufacturability and reliable mechanical performance. Certain compounds from the Stanyl® product range were selected on the basis of material properties, structural and manufacturing simulations. The PA46 is a unique high-performance polyamide known for its excellent stiffness, strength and fatigue resistance even at high temperatures. In addition, it offers excellent wear, abrasion and corrosion resistance as well as favorable friction properties that are ideal for gearbox applications.
Stanyl® PA46 results in gear designs with significantly better torque-to-weight ratios than when using metals. At the same time, it enables very high reduction ratios. Both these features support the development of lightweight, reliable and durable gearbox systems, especially for robotics. "Previous market solutions made of plastic often did not meet the stiffness and precision requirements needed for high-torque robotic gearboxes. The new combination of Stanyl® PA46 and SENTImotion's tooth geometry offers a major advance in this area," said Ron Krotwaar, expert in lightweight technologies at Envalior.
In addition to their lower density, plastics have a general advantage over metals because they enable the cost-reducing integration of functions such as mounts, guides and fastenings into the respective component. These functions are taken into account in the design from the outset and therefore do not have to be implemented in separate process steps, unlike metal designs. This reduces the total number of components required for the gearbox. The injection molding process also produces ready-to-assemble components. Post-processing steps such as milling, polishing or hardening are therefore no longer required. This is a major economic advantage, especially when it comes to manufacturing components in large quantities.
Lightweight, affordable robots start with the right gearbox design
Gearboxes account for around half of the total costs of metal robots simply due to their large number and contribute significantly to their high weight. For example, a standard robot arm with seven degrees of freedom of movement usually contains seven gears, so that the total number of gears in a humanoid robot adds up to more than 30. Therefore, designing the gears in lightweight plastic results in robots that are more than 20% lighter than their metal counterparts.
The significantly lower weight of a robot arm with plastic gears also has advantages for its dynamic behavior. It can be actuated with less force, which reduces the robot's energy consumption. The arm also reacts faster. In addition, the lower inertia of the arm increases the so-called safe speed, which benefits the robot's productivity. This allows it to complete its tasks faster, more efficiently and therefore more economically. The requirements for safe speed are defined in the ISO/TS 15066 standard. Among other things, it specifies how fast robots may interact with humans in order to avoid injuries. The high safe speed of the plastic gears significantly exceeds the requirements of the standard and therefore has the potential to be the impetus for an update of the standard.
For more information, visit Envalior at automatica (Hall B4, Stand 328) or at https://www.envalior.com/en-us/products.html.
Detailed information on Envalior's materials can be found in Envalior's MaterialAdvisor, which provides digital tools and services that customers can use to find, select and evaluate materials.
The new gearbox concept for robot arms enables the entry into the cost-effective large-scale production of lightweight and energy-efficient robots.
Photo: Envalior
The individual components of SMFdrives. Thanks to the polyamide 46 Stanyl® and a weight-optimized design, the gearboxes weigh around half as much as their metal counterparts. Production costs are approximately 50% lower.
Photo: Envalior
About Envalior
Envalior is a global leader in Engineering Materials with over 4,000 employees worldwide. It was established in 2023 through the merger of Lanxess Performance Materials and DSM Engineering Materials. With a long track record of customer-driven innovation, Envalior specializes in developing sustainable and high-performance material solutions. Focus markets include Automotive, New Mobility, Electronics & Electrical, and Consumer Goods. For more information, visit www.envalior.com.
Candace Roulo
tel: +1 248 200 8919
