Accordingly, the requirements placed on artificial hands are extremely high. They should not feel like a technical foreign body but instead integrate seamlessly and intuitively into everyday life. Achieving this goal requires developers to overcome a wide range of technical, functional, and ergonomic challenges.
Prosthetic Hands and Robotic Hands – Two systems, similar requirements
While the development of prosthetic and robotic hands is comparable in many respects, the main difference lies in the type of control.
Prosthetic hands are controlled directly by the user and function only in combination with the person who wears it. The required control signals are generated by the electrical activity of the remaining muscles, known as myoelectric signals. These signals are extremely weak and typically lie in the range of ±80 µV. They are captured via electrodes, amplified, and translated into movements of the motorized drive units. For a prosthesis to function reliably and precisely in everyday use, a certain training and learning phase for the user is essential.
The performance of a prosthetic hand – in terms of speed, force, precision, or repeatability – largely depends on its mechanical and electrical design. Decisive factors include the number of drives used, the force transmission concept, the overall efficiency, and the selected motor technology.
The main difference compared to today’s robotic hands lies in their significantly higher level of system complexity. They are considered “modern” or “state of the art” particularly because they require a much larger number of drive units per hand – typically between 12 and 20, positioned directly within the hand itself and the wrist. In addition, they feature a higher number of degrees of freedom, advanced control architectures and intuitive control strategies, as well as extensive sensory feedback systems. This high actuator density enables exceptional dexterity and fine motor movements that closely resemble the human hand.
The mechanical design is complemented by intelligent control concepts, closed-loop control systems, and sensory feedback. Tactile feedback, sensitive grip detection, and early forms of proprioception – the hand’s self-perception – are key prerequisites for safe, precise, and intuitive movements.
Depending on the application, backdrivability or non-backdrivability plays a crucial role in the design of robotic hands. Different tasks require different transmission characteristics. Backdrivable systems enable natural compliance within the drivetrain, allowing safer interaction with the environment and improved force sensing. Non-backdrivable systems, on the other hand, can hold loads without continuous power and provide greater stability for demanding or heavy-duty tasks. Choosing between these two concepts is therefore a key design decision when developing robotic gripping systems.
The performance requirements further highlight the differences: a robotic hand must operate significantly faster than a prosthetic hand in order to execute dynamic, precise, and adaptive movements reliably.
What makes modern hands state of the art
In addition to functionality and precision, weight and energy efficiency play a decisive role. Despite their high level of complexity, modern robotic and prosthetic hands must remain lightweight — typically between 300 and 500 grams — while still enabling long battery life. This is only possible through drive systems with very high power density and efficient motor and gearbox technology. These are precisely the characteristics offered, for example, by FAULHABER SXR family motors: thanks to their innovative hexagonal winding technology with a high copper fill factor, as well as diameter-compatible combination options, they achieve outstanding efficiency.
Equally important for robotic hands are everyday usability and robustness. Fundamental requirements include a waterproof, easy-to-clean design and high mechanical durability — both in prosthetics and robotics. Only when technology, reliability, and user comfort come together can a hand truly be considered “state of the art.”
Technological drivers of recent years
In recent years, multi-jointed, high-precision hand designs have played a major role in advancing development. The goal has been to replicate the natural mobility of the human hand as realistically as possible. Modern hands now feature multiple independently controlled joints, allowing individual fingers to be moved selectively. This significantly increases dexterity and enables complex gripping and manipulation tasks.
Finely graduated grip patterns also ensure that both delicate and powerful gripping operations can be performed safely. At the same time, advances in motors, gearboxes, and control technology have made drive systems more compact, efficient, and precise. This has a direct impact on motion quality and enables smooth, natural hand movements.
Key challenges on the path toward the human hand
Despite all progress, technically replicating the human hand remains one of the greatest challenges in robotics and prosthetics. Particular importance is placed on the interaction between technology, functionality, and user acceptance.
One critical aspect is noise generation. Motors, gearboxes, and mechanical components must operate extremely quietly so that the hand feels natural and is not perceived as disruptive in everyday use – a decisive factor for acceptance, especially in prosthetics.
Another technical challenge is further increasing the number of degrees of freedom. Many current systems are still limited to basic movements such as opening, closing, and simple thumb rotation. Truly human-like motion, however, requires additional lateral and individual finger movements.
Sensory feed is another central topic. Feedback on grip force, temperature, or surface texture is essential for natural interaction. However, particularly fine, intuitively perceptible feedback has not yet reached full production maturity.
Added to this is the challenge of integrating high performance into an extremely small installation space. Motors, gearboxes, sensors, and electronics all compete for space, while demands for power density, efficiency, and aesthetics continue to rise.
Interdisciplinary collaboration as the key to progress
Today, real progress in the development of robotic and prosthetic hands is achieved primarily at the interfaces between disciplines. Medicine, materials science, computer science, sensor technology, and drive technology must work closely together to create technically sophisticated yet everyday-ready solutions.
Medical expertise provides an understanding of anatomy, biomechanics, and user needs. Materials science enables lightweight, robust, and aesthetic structures. Computer science and control engineering deliver intelligent control, learning-capable systems, and efficient data processing. Only this close integration leads to solutions that not only function but are also accepted.
Requirements for developers – today and tomorrow
The development of robotic hands is among the most demanding tasks in modern robotics. It requires in-depth knowledge of mechanics, electronics, control engineering, artificial intelligence, and human–machine interaction. Currently, topics such as the kinematics and dynamics of multi-finger systems, precision actuators, sensor integration, and material selection are in focus.
In the future, soft robotics, bio-inspired mechanisms, and intelligent materials with adaptive stiffness will gain increasing importance. At the same time, solid electronics and embedded systems expertise is essential – from motor drivers and microcontrollers to real-time control and energy-efficient architectures. Control engineering and motion planning are also evolving toward learning-based, adaptive systems that combine classical approaches with AI methods.
The artificial hand of the future is shaped by technical excellence, interdisciplinary thinking, and a deep understanding of the human being. It is precisely within this field of tension that the question is decided as to whether a highly advanced machine becomes a truly human-centered solution. Taking this idea one step further, it also becomes clear that other joints and movement patterns place equally demanding requirements on mechanics and drive technology.
This is why the FAULHABER BXI was conceived in new dimensions and with optimally coordinated features. It has been developed specifically to meet the high demands placed on joints in current and future robotics applications. The drive system consists of a single unit combining motor, integrated multi-stage planetary gearbox, and high-resolution encoder. Its key strength lies in its compactness: maximum performance in minimal space. After all, intelligent, compact drive systems are what keep evolution in robotics moving forward.