Application And Development Analysis Of Composite Materials in Humanoid Robots

The application of composite materials in humanoid robotics is driving a "skeletal revolution," significantly enhancing robots' mobility, endurance, and environmental adaptability through lightweight design, high strength, and functional innovation. The following analysis explores four dimensions: application value, core materials, technological trends, and supply chain challenges:

I. Core Application Value: Breaking Through Performance Bottlenecks

1. Lightweight Efficiency

1.1 Traditional metallic materials (such as aluminum alloys) have high density, limiting robots' flexibility and endurance. Composite materials like PEEK have a density of just 1.3 g/cm³ (half that of aluminum alloys), enabling Tesla's Optimus to reduce weight by 10 kg and increase walking speed by 30%.

1.2 Carbon fiber-reinforced PEEK (CF/PEEK) has a density of 58% that of aluminum alloy, significantly reducing energy consumption while maintaining equivalent strength.

2. High Strength and Wear Resistance

2.1 PEEK materials have a bending strength of 35 MPa and a friction coefficient as low as 0.02 (equivalent to one-fifth that of ice), extending the lifespan of joint components by three times and enabling 20,000 hours of maintenance-free operation (e.g., ABB collaborative robots).

2.2 The finger joints of Boston Dynamics' Atlas use PEEK composite materials, with an impact strength of 180 MPa and a gripping force error of <0.1 N, enabling precise operations.

3. Functional Integration Expansion

3.1 Self-lubricating properties reduce wear on transmission components, while self-healing materials (such as microcapsule polyurethane coatings) can repair 0.3 mm scratches within 48 hours, extending the lifespan of the housing by three times.

3.2 High-temperature resistance (PEEK can withstand temperatures up to 250°C for extended periods) and electromagnetic shielding (magnesium alloy) expand application scenarios in extreme environments.

II. Mainstream Composite Material Technology Routes and Application Scenarios

(1) Special Engineering Plastics: PEEK Dominates Core Transmission Components

• Application Scenarios: Gears, bearings, joint frames

• Performance Advantages: High rigidity, self-lubrication, chemical corrosion resistance. A single humanoid robot uses approximately 6.6 kg of PEEK (1 kg pure PEEK + 5.6 kg CF/PEEK), reducing weight by 40% compared to metal.

• Case Study: UBTech Walker S uses PEEK reducers to balance load and weight; Tesla Optimus replaces metal with PEEK in the harmonic reducer's gear wheel.

(2) Carbon Fiber Reinforced Composites: The Mainstay of Lightweighting

• Technical Form: CF/PEEK Pre-impregnated Materials (Melt Impregnation/Powder Suspension)

• At 70% carbon fiber volume content, tensile strength is comparable to titanium alloy, with a density of only 36% of titanium alloy.

• Applications: Kent Co., Ltd.'s CF/PEEK prepreg is used in aircraft flap actuators to achieve a 40% weight reduction; Guangwei Composite Materials' medical-grade products are compatible with orthopedic robotic arms.

(3) Lightweight Metal Alloys: Magnesium Alloy as the Cost-Effective Choice

• Application scenarios: housings, structural supports

• Weight reduction performance surpasses aluminum (magnesium-to-aluminum price ratio of 0.87), with improved electromagnetic shielding and heat dissipation efficiency. Baowu Magnesium Industry's industrial robots achieve 11% weight reduction and 10% energy savings.

• Semi-solid process solves corrosion resistance issues and is suitable for small parts of humanoid robots.

(4) Bionic and Smart Materials: The Next Breakthrough

• MX6 Bionic Material: Dynamic deformation rate >300%, friction coefficient 0.02, wear rate reduced by 72%, used in flexible joints (e.g., transmission components of surgical robots).

• Shape Memory Alloys: Joint bending angle approaches 180°, simulating human range of motion.

III. Development Trends and Technological Evolution Directions

1. Material Performance Optimization

1.1 Addressing PEEK Low-Temperature Brittleness: Enhanced through carbon fiber/glass fiber modification, developing low-temperature toughness grades.

1.2 Composite process upgrades: RTM (resin transfer molding) reduces the production cycle of CFRP components from 4 hours to 45 minutes, with a 40% cost reduction.

2. Intelligence and functional integration

2.1 Sensor embedding: PEEK's insulating properties enable integration with electronic components, achieving structure-function integrated design.

2.2 Self-sensing materials: Developing stress-to-electric signal responsive materials to monitor the load status of robotic arms in real time.

3. Green Sustainability

3.1 Bio-based Materials: Bio-based PA610 (renewable raw materials ≥40%) reduces carbon footprint by 35%, aligning with EU RoHS 3.0 standards.

3.2 Recycling Technology: Thermoplastic composites (e.g., PPS) can be melted and reshaped, promoting a circular economy.

IV. Industry Chain Landscape and Challenges

4.1 Industry Chain Map and Domestic Production Progress

4.2 Current Bottlenecks

• Cost constraints: The unit price of PEEK is approximately 300,000 yuan per ton (with fluoroketone accounting for 50% of the cost), and cost reduction through scale depends on expanding production capacity.

• Processing barriers: PEEK injection molding requires specialized high-temperature equipment (such as that provided by Haitian International), and the yield rate for precision gear processing needs to be improved.

• Lack of Standards: Fatigue testing for thermoplastic composites and long-term reliability databases remain incomplete.

V. Summary: Future Growth Engines

5.1 Market Potential: By 2025, the global humanoid robot market size will exceed 5 billion USD, with lightweight materials accounting for over 20% (PEEK reaching 3.5 billion RMB).

5.2 Innovation Focus: Biomimetic materials (e.g., MX6), smart responsive composites, and supercritical recycling technology.

5.3 Domestic Opportunities: Fluoroketone raw materials (Xinhuan New Materials), PEEK polymerization (Zhongyan Co., Ltd.), and CFRP prepregs (Kent Co., Ltd.) are accelerating the replacement of overseas giants.

Composite materials are evolving from "passive load-bearing" to "active empowerment." The flexibility, endurance, and intelligence of future humanoid robots will deeply depend on material innovation-this is not only a technological competition but also a window of opportunity for supply chain restructuring.

Source: www.frpapp.com