How to Engineer Precision Seals for Sustainable Mobility & Electric Aircraft

Next generation aircraft such as eVTOL, hybrid electric, and hydrogen-powered aircraft are taking sustainability and mobility to a higher level ... with increasing challenges related to thermal control, wear resistance, and material compatibility. Sealing solutions need to perform reliably across wide temperature ranges, varying loads, and complex system architecture.

This FAQ addresses common engineering questions about sealing and material selection for next generation aircraft, with responses based from Omniseal Solutions’ recent webinar, Sealing Solutions & Material and Friction Control for eVTOLs, Hybrid Systems & Hydrogen Aviation.

Electric and UAM aircraft operate under fundamentally different conditions compared to conventional combustion-based platforms. High-speed electric motors, compact drivetrain designs, elevated voltages, and integrated thermal management systems place increased demands on sealing components.

Unlike traditional engines, electric propulsion units (EPUs) experience rapid rotational speeds and wide thermal fluctuations, often in very confined spaces. Seals must perform reliably while maintaining tight tolerances, preventing leakage of lubricants or coolants, and protecting sensitive components from contamination. In many cases, seals are also exposed to dielectric fluids used for thermal control, which introduces additional chemical compatibility requirements.

For more details, access our Advanced Air Mobility Handbook.

Material selection is one of the most important factors in sealing design for electric aircraft. Polymer-based composites and high-performance polyimides are widely used as they provide a balance of thermal stability, electrical insulation, and mechanical strength. commonly used as thermal barriers in these environments.

Polyimide materials are commonly used as thermal barriers as they retain their structural integrity at sustained temperatures versus conventional polymers, which allow them to operate close to heat-generating components (motors, bearings, and power electronics) without degradation. Their naturally low moisture absorption and dielectric properties also support reliable electrical insulation in high-voltage environments.

In high-speed rotating systems, sealing reliability is determined by both the intrinsic properties of the material and the precision of the seal design. Rotary shaft seals must maintain consistent contact pressures while minimizing friction against the shaft surface.

Low-friction, wear-resistant polymers are often selected for high-speed applications to handle elevated surface speeds and thermal loads without excessive wear. By carefully optimizing lip geometry and contact force, engineered seals can retain lubricants while excluding contaminants such as dust or moisture. This balance helps protect both the seal and the rotating component, reducing system wear and extending service intervals.

Compact packaging further increases the importance of precision. Since electric aircraft designs often allow little margin for misalignment or vibration, seals must be designed for tight installation envelopes in order to support long-term reliability.

Precision sealing solutions play an increasingly critical role in the reliability and efficiency of eVTOL, hybrid electric, and hydrogen-powered aircraft. As propulsion technologies evolve, seals must be designed as functional system elements—supporting thermal management, wear control, and long-term performance across demanding operating conditions.

By combining advanced materials, engineering expertise, and application specific validation, Omniseal Solutions works with customers to solve the technical challenges of UAM and next generation aircraft platforms. For engineering and procurement teams, early collaboration and application-driven seal design remain key to meeting performance, safety, and lifecycle objectives.

To learn more about sealing solutions and wear and friction control materials for next generation, commercial, and general aviation applications, visit our Aviation Industry Infographics.