Like the evolution from bulky cassette-based Walkman to today’s pocket-sized smartphones that can store and play tens of thousands of songs — modern engineering also demands greater capability within dramatically reduced physical footprints. Whether it’s surgical robots that must fit advanced sensors into tight spaces, or aircraft systems where lighter parts translate directly into fuel savings, miniaturisation brings both opportunities and challenges in design. Here, Chris Handcock, design lead at drive system supplier Electro Mechanical Systems, explores how miniaturisation is changing product design.
Over the past 20 years, we’ve seen huge cube-like TVs shrink to a centimetre thick, while terabytes of data can now sit on a chip no bigger than a fingernail. This change is apparent across industry too. Smaller, lighter, more efficient systems offer clear advantages, but miniaturising drive systems isn’t simply a matter of scaling down existing motor designs. It must carefully balance torque, power density, motor type and thermal management.
Accelerating miniaturisation across industries
Medical devices such as minimally invasive surgical tools, diagnostic sensors and compact implantable systems require tiny, high-performance components. Take for example, robotic-assisted laparoscopic surgery. Here, miniature drive systems are used to actuate wristed end-effectors within instrument shafts often less than 10mm in diameter. These systems must deliver high torque at low speeds to enable precise articulation, while maintaining minimal backlash and low inertia for accurate, repeatable motion. Thermal performance is tightly constrained because heat generated within the motor or gearbox must remain below thresholds that could affect surrounding tissue. As a result, the motor’s architecture, gear reduction, materials selection and thermal modelling become critical at the first point of design.
In aerospace and automotive applications, every gram of weight removed can contribute to greater fuel efficiency, reduced payload, and better design flexibility. Whereas, in industrial automation, robotics and consumer electronics increasingly rely on compact motors and electronics to deliver power and precision in confined spaces.
While each sector seeks different benefits of miniaturisation, they all share the same set of pressures — limited space, demand for mobility or portability and a need for functionality without bulk. As a result, shrinking component size has become a strategic choice and designers are rethinking the architecture, materials and even manufacturing techniques to meet these demands.
A question of compromise
But reducing size can bring trade-offs. Small motors do not automatically deliver output as larger ones. To meet the same standards, engineers must carefully consider factors like torque output, power density, load-handling capability and energy efficiency. Smaller motors tend to have lower torque, meaning that designers may need to compensate with gearing, high-performance materials or alternative motor types.
Here, selecting the correct micro motor technology becomes critical. For example, coreless DC motors may suit applications where dynamic response and low inertia matter, such as medical or robotic systems. On the other hand, brushless DC motors, like those from FAULHABER, may provide a better balance of efficiency, lifespan and power-to-weight ratio for aerospace applications.
Although they offer precise control, stepper motors can be less efficient and more challenging to integrate at very small scales. In each case, motor type, winding geometry, magnet strength, gearheads, feedback systems and controls must be tuned to ensure performance without exceeding the constraints imposed by size.
Achieving precision through custom design
Another engineering challenge that presents with miniaturisation is thermal management. As motors get smaller, they lose surface area relative to the amount of heat they generate. High power density in a compact space can lead to heat accumulation, which can degrade performance, reduce efficiency and damage components.
To mitigate this, designers must address heat as an integral part of the design process rather than as an afterthought. Solutions could include optimising magnetic materials, improving insulation, designing housings or airflow paths to aid heat dissipation, or embedding thermal sensors. In some cases, compact systems might incorporate heat-spreading housings, micro-cooling channels and other advanced thermal management features.
Addressing these considerations at the start of a concept is essential, as thermal limitations can dictate the performance envelope of a miniature motor. This is where precision manufacturing becomes crucial. Off-the-shelf motors and gear systems are often unable to meet the tight spatial, mechanical and performance constraints associated with tiny applications.
For bespoke solutions, consider selecting a partner such as EMS, which provides a comprehensive custom design and manufacturing service, from its UK based facility.
Miniaturisation is reshaping engineering, but consequently driving new expectations for performance, efficiency and design across every sector. Small, lightweight components now unlock capabilities that once seemed impossible. But real success demands more than shrinking hardware — it requires careful consideration of motor selection, uncompromised manufacturing precision and the support of custom design solutions.
To learn more about the custom design service provided by EMS, visit the website or get in touch with a member of the team.
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