Motors for medical technology Compact drives for surgical robots, medical cobots, exoskeletons, and prostheses
Medical technology applications place high demands on precision, weight, torque, and installation space. Whether surgical robot, medical cobot, exoskeleton, or motorized prosthesis: the drives must carry out movements with fine controllability, be compactly integrated, and reliably respond to changing requirements.
TQ-RoboDrive offers frameless motors for medical technology, custom actuators, and integration services. Our ILM and ILM-E servo motors combine high precision with low weight and high torque density. Different diameters, overall lengths, and winding configurations enable targeted optimization for the torque, speed, voltage, and installation space of the respective application.
Which motors are suitable for medical technology applications?
Frameless servo motors are particularly suitable for compact and precise medical technology applications. Their frameless design allows the stator and rotor to be directly integrated into the device construction and combined with bearings, gearbox, sensor technology, and electronics to form a compact actuator.
Which motor series is suitable depends on the respective application. The ILM series is particularly recommended for delicate and highly precise systems with high requirements for smooth running, dynamics, thermal load capacity, and customized design. These include, for example, surgical instrument axes, surgeon consoles, and sensitive medical cobots.
The ILM-E series is the lightweight and cost-optimized alternative for scalable applications and higher quantities. It is particularly suitable for exoskeletons, prostheses, and mass-produced medical cobots. Hall and temperature sensors are integrated as standard and support compact motor integration.
Regardless of the selected series, various diameters, stack lengths, and winding configurations are available. This allows us to tailor the motors precisely to the application's load, motion, and temperature profile.
What are the most important characteristics of motors used in medical technology
Highest precision
Surgical systems, medical cobots, and motorized assistive devices must perform movements in a controlled, reproducible, and finely adjustable manner. Smooth motor operation and precise controllability support slow positioning movements as well as dynamic motion sequences. Especially in instrument axes and sensitive robotic systems, even minor torque fluctuations can affect motion quality.
Lightweight
In body-worn systems, mobile devices, and robot arms, every additional weight affects handling, energy consumption, and upstream axes. Lightweight motors support compact joints and reduce moving mass. This is especially relevant for exoskeletons, prostheses, surgical instruments, and medical cobots.
Maximum torque density
Medical technology systems often have only limited installation space, yet must still provide sufficient force. High torque density enables powerful drives with compact dimensions. The decisive factor here is the ratio of torque to weight and installed volume — for example in robotic arms, body-worn assistive systems, or compact tool axes.
Which TQ motors do we recommend for which medical technology application?
Medical cobots
Medical cobots support medical personnel, for example during treatments, examinations, or physically demanding tasks. Because they interact directly with people, their movements must be precise, controlled, and finely adjustable.
In addition to high precision and torque density, smooth operation, low inertia, and compact sensor integration are important. Depending on precision requirements, thermal load, and production volume, both the ILM and ILM-E series are suitable.
For highly sensitive and individually designed systems, the ILM series is often the first choice. For scalable platforms and higher production volumes, the ILM-E series offers a lightweight and economical alternative with Hall and temperature sensors integrated as standard.
Surgical robots
Robot-assisted surgical systems include several drive areas with different requirements:
- Surgeon console: precise capture and, if applicable, sensitive feedback of the operator movements
- Robot arm: compact, high-torque, and precisely controllable joint drives
- Robot tool: miniaturized and highly precise drives for instruments and tool axes
For surgical robots, we primarily recommend the ILM series. It includes particularly small sizes and is suitable for applications with high requirements for precision, synchronous operation, dynamics, and customized design.
For slow and finely dosed movements, low cogging is also important. It reduces torque fluctuations and supports smooth motor operation. In compact instrument axes, low heat generation, precise sensing, and suitable thermal coupling also play a central role.
For higher production volumes and a suitable requirement profile, the ILM-E series can also be used. The specific selection depends on joint function, load profile, precision requirements, thermal behavior, and economic conditions.
Exoskeletons
Exoskeletons support human movement and reduce the strain on the body when lifting, carrying, or walking. Since the actuators are positioned directly on the body, low weight, compact dimensions, and a natural response behavior are especially important.
In addition, the actuator must respond quickly to movement intentions and provide the required support in a controlled manner. In passive or transparent operation, it should follow the user's movements with as little perceptible resistance as possible. For this, low mass inertia, a suitable gear ratio, and sensitive control are relevant.
For scalable exoskeleton applications, we primarily recommend the ILM-E series. It combines low weight and high torque density with cost-optimized manufacturing, making it especially suitable for body-worn systems in higher volumes.
Prostheses
Motorized prostheses must support movements in a confined installation space without burdening the user with unnecessary weight or excessive heat generation. Therefore, compact dimensions, a good torque-to-weight ratio, and efficient operation are crucial.
In addition, smooth response characteristics, low noise generation, and precise coordination of motor, gearbox, sensors, and control are relevant. Since the drive is worn directly on the body, thermal management and continuous operation must also be considered at an early stage.
Depending on the joint, size, and precision requirements, compact ILM motors or ILM-E variants may be suitable. The ILM series is particularly well suited for delicate and individually designed applications. For scalable prosthetic systems and higher production volumes, the ILM-E series offers a lightweight, cost-optimized alternative.
Thanks to its frameless design, the motor can be integrated directly into the prosthesis’s mechanical structure. The housing, bearings, gearbox, sensors, and heat dissipation can therefore be specifically tailored to the application.
Success stories from medical technology
Sensodrive: Sensitive drive modules for medical robotics
Sensodrive develops torque-controlled drives for medical technology and industrial automation. For the compact SensoJoint drive modules, the company relies on ILM frameless servo motors from TQ-RoboDrive. What matters are the high precision, compact integration, power density, and dynamic controllability.
upstair: compact drive for patient transport
The startup upstair develops a stair-climbing transport aid that relieves emergency responders during patient transport. For the stair-climbing and drive system, motors from the ILM-E series by TQ-RoboDrive are used.
The compact and lightweight design supports a low system weight. At the same time, the high torque density enables powerful driving and climbing operation in a limited installation space.
EASE: Sensitive drives for intelligent exoskeletons
EASE develops intelligent exoskeletons to relieve the strain on people who work physically demanding jobs. ILM-E motors from TQ-RoboDrive enable fast and highly responsive performance with low gear ratios and speeds.
In transparency mode, the exoskeleton can follow the user’s movements with minimal noticeable resistance. When needed, the drives dynamically provide the desired support. EASE is working to bring the new system generation with TQ drives to series production readiness.
FAQs about motors for medical technology
Why are frameless motors suitable for medical technology?
Frameless motors are suitable for medical technology because they combine the highest precision, low weight, and maximum torque density. Since they do not have their own motor housing, complete bearing system, or separate motor shaft, the stator and rotor can be integrated directly into the device design. This allows the mechanics, sensors, gearbox, and thermal connection to be specifically tailored to surgical robots, medical cobots, exoskeletons, or prostheses.
Which motors are suitable for medical cobots?
For medical cobots, compact frameless servo motors with high precision, torque density, and sensitive controllability are ideal. Smooth synchronism and low mass inertia support controlled movements during interaction with humans. For particularly sensitive or custom-designed systems, the ILM series is often a suitable option. For scalable platforms and higher production volumes, the ILM-E series offers a lightweight and cost-optimized alternative.
Which motors are suitable for surgical robots?
For surgical robots, compact frameless servo motors with high precision, low cogging, and smooth motor operation are suitable. Particularly small ILM sizes are suitable for instrument axes, tool axes, and surgeon consoles. In the main axes of the robot arm, the selection also depends on continuous and peak torque, installation space, sensor technology, and thermal connection. If the requirements are suitable, the ILM-E series can also be used.
Why is low cogging important in medical technology?
Low cogging reduces torque fluctuations and supports smooth motor operation. This makes slow, finely controlled movements more precise and repeatable. This is particularly relevant for surgical instrument axes, sensitive robotic arms, surgeon consoles, and motorized prostheses. Motion quality also depends on sensors, control systems, gearing, and mechanical integration.
Which motors are suitable for exoskeletons?
For exoskeletons, lightweight and compact frameless motors with high torque density and dynamic response are suitable. In addition, low inertia, sensitive control, and a suitable gear ratio are important so that the drive can follow the user’s movements. For scalable exoskeleton systems, TQ-RoboDrive primarily recommends the ILM-E series, as it combines low weight with cost-optimized production.
What matters in motors for prostheses?
When it comes to motors for prostheses, low weight, compact dimensions, high torque density, and efficient operation are crucial. In addition, smooth running, noise behavior, thermal load, and response characteristics should be taken into account. Depending on the joint and precision requirements, compact ILM motors or ILM-E variants may be suitable. The frameless design enables direct integration into the prosthesis’s mechanical structure.
Are TQ motors certified as medical devices?
TQ-motors are components within a medical technology system and are not automatically approved as a complete medical device. Regulatory assessment and approval are carried out for the respective end product and its intended use. TQ-RoboDrive supports the technical selection, design, and integration of the motor. However, responsibility for the overall regulatory system must be defined on a project-specific basis.