With the growing demand for more efficient electric motors, especially in the fields of e-mobility, aviation and space exploration, lightweighting in rotor and stator design has become a top priority for engineers. New materials and design innovations are transforming how we approach motor efficiency, energy savings and sustainability. Here, John Morehead, principal consultant at Motion Mechatronics and advisory board member at CWIEME Berlin, explores developments in rotor and stator lightweighting and the future of electric motor technology.

In the ever-evolving landscape of electric motor technology, the push toward lightweighting has emerged as a critical factor influencing design and manufacturing. As industries increasingly prioritise sustainability, the benefits of reducing weight in electric motors extend beyond mere efficiency — they play a pivotal role in enhancing performance, reducing costs and contributing to a greener future.

Statistics show that in 2024, the global EV market is anticipated to generate a revenue of $786.2 billion. Over the next five years, the market is expected to maintain a steady annual growth rate of 6.63 per cent, bringing the projected market volume to $1,084 billion by 2029. Additionally, unit sales are forecasted to reach 18.84 million vehicles by the same year, underscoring the sector’s robust and sustained expansion.

Weight reduction

One of the key areas of focus in electric motors should be weight reduction. Electric motors tend to be heavy because they are primarily made of metal components, and as the power output increases, this weight concern grows. In my experience, there’s a strong push for electric motors to not only be smaller and lighter, but also faster and denser in terms of power and torque. In the last decade, the rise of e-mobility has significantly influenced this industry. Before that, we didn’t see much emphasis on lightweighting.

With e-mobility gaining traction, particularly in two-wheelers and small commercial vehicles, the focus on reducing weight in electric motors became critical. This is essential not only for extending battery life, but also for enhancing flexibility and usability in smaller applications. The aeronautics sector is also making strides in electric aviation, where weight is paramount. The innovations and practices that emerge from this high-level focus will trickle down to the electric motor industry as a whole.

Reducing weight can also lead to cost savings and a significant reduction in carbon emissions, which is an imminent and continuously growing concern in today’s industry. Furthermore, there’s a burgeoning interest in the circular economy, and I see electric motor manufacturers starting to design their products with reusability and recyclability in mind.

The emergence of start-ups

Another area impacting the industry is the emergence of start-ups. Historically, it was quite challenging for start-ups in the electric motor sector to gain traction. Many new companies struggled to secure commercial orders due to customers’ reluctance to work with unproven entities. However, the landscape has changed. Many of the companies driving innovation in e-mobility and electric aviation are themselves relatively new. They are more open to collaborating with start-ups and incorporating innovative components that enhance their technology.

This shift has made it easier for new motor technology companies to enter the market. Just ten years ago, concepts like axial flux motors were relatively niche, but now they’re gaining popularity, largely due to e-mobility. While the manufacturability of axial flux designs still presents challenges, rapid advancements are on the horizon, particularly with new soft magnetic composite materials that facilitate easier production.

New materials

The electric motor industry is in a period of rapid evolution. Companies that have long relied on traditional materials, like cast iron, are starting to explore alternatives like aluminium for motor enclosures. Aluminium could provide sufficient durability for over 90 per cent of industrial applications.

We’re also seeing exciting developments with entirely new materials, such as carbon nanotubes, and advances in 3D printing technology. Although 3D printing for motor stators isn’t widely adopted for mass production yet, its potential to revolutionise motor manufacturing is clear. Additionally, innovations like electrostatic motors are pushing the envelope on weight reduction and material efficiency.

The merging of motors and control technologies is another significant trend. The integration of microprocessor power, power electronics and sophisticated software algorithms allows for the design of higher performance motors that can effectively address certain limitations. This convergence is transforming the industry from a purely electromechanical focus to a more holistic approach that includes electronics and software, enhancing overall motor performance and efficiency.

Aerospace

The advancements in electric motor technology are profoundly impacting both the aviation and space sectors. For instance, as electric aviation continues to grow rapidly, weight reduction becomes a critical factor in designing electric motors. This trend is pushing us to explore innovative designs and materials that can significantly lower the weight of motors without sacrificing performance.

In the space sector, new entrants like SpaceX are driving innovation. They challenge the traditional, conservative approaches that have dominated the industry for so long. Start-ups are now more willing to adopt cutting-edge technologies, which encourages us to rethink electric motor designs and their applications. This collaborative environment between established firms and newcomers leads to exciting developments, ultimately making electric propulsion systems more efficient and viable for aerospace.

The circular economy

The circular economy plays a significant role in electric motor manufacturing by encouraging manufacturers to rethink the lifecycle of their products. In the past, electric motor manufacturers did not typically design their products with recyclability in mind. However, there is a growing trend where companies are now focusing on making electric motors that are not only reusable but also recyclable to a higher degree. This shift is crucial, as it helps reduce waste and resource consumption in the production process.

For instance, by optimising designs and materials, manufacturers can minimise the use of raw materials, which contributes to lower carbon emissions. Additionally, with advancements in technology, we can explore innovative ways to recycle components and recover materials at the end of a motor’s lifecycle. This approach not only aligns with environmental sustainability goals but also presents opportunities for cost savings and efficiency improvements in production. Overall, integrating circular economy principles into electric motor manufacturing is a vital step towards a more sustainable and responsible industry.

Look to the future

The future of the electric motor industry is incredibly promising. With new players entering the market, we can expect to see a plethora of innovations. The existing large motor companies may have long histories, but they face competition from upstart firms that bring fresh perspectives and novel technologies.

As we move forward, we can expect to see more electric motors designed with integrated controls. The importance of software in optimising motor performance cannot be overstated. We're at a point where the pace of technological advancement is accelerating, and what seems expensive and exotic today could be commonplace within the next decade. As the industry embraces new materials, designs, and integration strategies, we will see a future where electric motors are lighter, more efficient and increasingly integral to various applications, from industrial uses to personal mobility solutions.

Register your interest in CWIEME Berlin 2026, taking place from 19-21 May, connecting the leading coil winding and electrical manufacturing experts.