Material Innovation for Humanoid Robots: Diversified Applications from PEEK to Organosilicon

In recent years, with the rapid development of generative artificial intelligence technology, the humanoid robot industry has gradually become a hot topic in the field of technology. Many domestic and foreign technology giants, such as Huawei, Xiaomi, Tencent, Tesla, and Yushu Technology, have joined this emerging track, intensifying market competition. According to industry reports, China's humanoid robot industry experienced explosive growth in 2023, with the industry scale rapidly increasing to 3.91 billion yuan and a year-on-year growth rate of up to 85.7%.

Looking ahead, it is expected that the humanoid robot industry will maintain a sustained high-speed growth trend in 2024 and 2025. By 2026, the scale of China's humanoid robot industry is expected to exceed the 20 billion yuan mark.

The Importance of Lightweight Technology

The lightweight technology of robot body, as a current research hotspot, is crucial for achieving close cooperation between humans and robots in narrow spaces, ensuring human safety during the cooperation process, and improving the mobility of robots. In many application scenarios, structural components such as shell materials, vertebrae, upper arms, lower arms, thighs, and calves cannot do without the support of lightweight materials. The commonly used materials for these structural components include steel, aluminum alloy, magnesium alloy, carbon fiber, and polymer materials.

▲ 2.1. Introduction to Polymer Materials

▲ Polyether ether ketone (PEEK)

In early 2024, Tesla launched the Optimus-Gen2 second-generation humanoid robot, which successfully reduced weight by 10 kilograms and increased walking speed by 30%. The key technology behind this is the use of lightweight materials such as polyetheretherketone (PEEK). PEEK material, as an essential raw material for the production and manufacturing of humanoid robots, provides strong support for the lightweight and high-performance of robots.

PEEK， The Chinese name is polyetheretherketone, which is a polymer composed of repeating units of ketone bonds and two ether bonds, belonging to the category of special engineering plastics. By compounding with materials such as carbon fiber and fiberglass, the performance of PEEK can be further improved. Especially when combined with carbon fiber, utilizing the high tensile strength and elastic modulus of carbon fiber, this composite material exhibits excellent toughness, impact resistance, specific strength, and thermal stability, thus demonstrating broad application prospects in the field of robotics.

▲ Polyamide (PA)

In the Poppy robot jointly designed by Ensta ParisTech and Flowers Lab in France, all components except for the motor and electronic circuit are realized through 3D printing technology, using selective sintering (SLS) process and polyamide (PA) as the printing material.

PPS material is superior to traditional metal materials in terms of lightweight and temperature resistance, and is suitable for various intelligent robot components, including human exoskeleton connectors, protective plates, power center housings, as well as gear and bearing components.

▲ 2.1.2.1. Liquid Crystal Polymer (LCP)

In ordinary industrial robots, the number of joints is usually between 2 and 10 axes. However, for humanoid robots, the number of joints is expected to exceed 40, such as Tesla's Optimus robot which has 40 joints.

LCP， Liquid crystal polymers, with their excellent fluidity, dimensional stability, high temperature resistance, and high-frequency dielectric stability, have become an ideal choice for precision components. It is not only suitable for micro motors, but also one of the preferred materials for high-frequency signal connectors due to its high-frequency performance and high temperature resistance.

▲ Carbon fiber composite materials

Carbon fiber reinforced plastic (CFRP), also known as carbon fiber reinforced plastic, is a composite material formed by the curing reaction between resin (mainly epoxy resin) and carbon fiber. This material has been widely used in various fields such as sports equipment, industrial products, as well as aircraft and automobile manufacturing.

Carbon fiber composite materials perform particularly well in the manufacturing of robotic arms due to their lightweight and sturdy properties. Research by domestic institutions shows that robotic arms made of carbon fiber composite materials have significantly reduced overall weight by 30% compared to aluminum alloy materials. This material is particularly suitable for robot components that require high strength and lightweight design.

▲ Organosilicon

Organosilicon, also known as organosilicon compounds, is a type of compound that contains Si-C bonds and at least one organic group directly attached to a silicon atom. They exhibit softness and skin friendliness, high and low temperature resistance, radiation resistance, non toxicity and odorlessness, as well as excellent biocompatibility and environmental stability. These characteristics make organosilicon play an indispensable role in various fields such as automobiles, airplanes, military technology, electronic devices, etc.

Organic silicon materials are widely used in the hand design of soft robots due to their flexibility, transparency, and biocompatibility, making them an ideal choice for performing fine operations and safely interacting with humans.

▲ 2.1.2.2. Thermoplastic elastomers (TPE)

Thermoplastic elastomers (TPE) exhibit rubber like elasticity at room temperature and can be plasticized into polymer materials at high temperatures. This material not only has mechanical properties similar to rubber, but can also be made or reused through the processing of thermoplastic materials.

TPE materials exhibit excellent performance in many aspects. Its convenient processing characteristics enable it to adapt to various processes such as injection molding, hot melt, and sol, and can be easily mixed with plastic materials such as ABS. This material also meets medical grade safety standards and has been widely used in multiple fields, especially in robot components that require comfortable texture and high durability.