Humanoid Robots’ Ultra-Tough Backbone: Titanium Alloys

With the launch of products such as Tesla Optimus Gen3, Huawei Kuafu and UBtech Walker X, the industry has stepped into a new stage. Humanoid robots have extremely high requirements for movement, endurance and stability, and traditional metals can hardly meet such demands. Titanium alloys have extended their applications from the aerospace industry to humanoid robots, becoming the key "skeletal" material that determines the robots' motion accuracy, load capacity and service life.

 

 

The core of humanoid robot design is to strike a balance between human-like performance and high performance: flexible movement, sturdiness and reliability, as well as lightweight design to reduce motor load and improve endurance.

 

High Specific Strength

Its strength is close to that of steel, while its density is only 60% of steel.For example, UBtech Walker X adopts a titanium alloy frame with a total weight of only 55kg; if steel were used instead, the weight would exceed 80kg, leading to a significant decline in flexibility.

 

Fatigue and Corrosion Resistance

Titanium alloys can withstand tens of thousands of high-frequency rotations of joints, with a fatigue life three times that of stainless steel, ensuring stable long-term operation. They also feature excellent corrosion resistance, making them suitable for complex environments.

 

Good Biocompatibility

They are non-repellent to human tissues, making them suitable for human-machine interaction scenarios such as medical rehabilitation robots and exoskeletons, and serving as a key material for realizing human-machine symbiosis.

 

Strong Process Compatibility

Titanium alloys can be made into complex structural parts through 3D printing, metal injection molding and other processes. Moreover, they are non-magnetic and will not interfere with the accuracy of sensors and control systems.

 

Titanium alloy parts in huamoid robots

 

 

Load-Bearing Frame and Core Joints

Load-bearing frames and core joints are the most core application scenarios of titanium alloys, directly determining the load capacity and movement flexibility of humanoid robots. Parts such as the robot's spine, hips and knees need to meet the requirements of high strength, high toughness and lightweight at the same time, making titanium alloys the optimal material choice.

 

Tesla Optimus Gen3 adopts a titanium alloy spine integrally formed by 3D printing, with its strength increased by 20% compared with traditional structures; its hip and knee joints use Ti-6Al-4V alloy gears and hollow structures, achieving a 40% weight reduction for a single joint and a fatigue life three times that of traditional stainless steel.

 

Precision Transmission and Actuation Components

In the precision transmission and actuation components of robots, titanium alloys can significantly improve motion accuracy and durability

In terms of end effectors, Festo's bionic hand from Germany uses 0.1mm titanium foil to package tactile sensors, which offers excellent electromagnetic shielding effect and is 30% thinner than aluminum alloy foils; the titanium-based flexible pressure sensor array developed by the Shenyang Institute of Automation of the Chinese Academy of Sciences has a resolution of 5μm and has been applied to the fingertip tactile module of Xiaomi CyberOne, enabling precise grasping.

 

Relying on the MIM process, titanium alloys can be used to produce micro gears with a diameter of less than 20mm, adapting to the complex structure of dexterous hands, realizing multi-degree-of-freedom movement in narrow spaces, and balancing lightweight design and high flexibility.

 

Special Scenario Adaptation

For components in long-term contact with the human body, such as the operating arms of medical rehabilitation robots and implantable joint stents, special titanium alloys such as Ti6Al7Nb are used.

 

Gr7 titanium-palladium alloy is resistant to corrosion by reducing acidic media, making it suitable for chemical special robots;

Ti5Al2.5Sn has outstanding low-temperature performance, maintaining toughness even at -253℃. The TX3 polar quadruped robot of Titanobotics from Norway adopts this titanium alloy frame and can perform continuous glacier monitoring for 72 hours at -58℃ in Greenland.

 

 

General-purpose Ti6Al4V (Gr5): It achieves the optimal balance between strength and cost, with mature 3D printing, machining and forging processes, and is used in most core load-bearing components.

 

Ti6Al4V ELI (Extra Low Interstitial Gr5): With lower impurity content, its impact toughness is increased by 30% at -40℃, making it suitable for deep-sea low-temperature, high-fatigue and high-impact scenarios such as harmonic flexsplines and grippers of medical robots.

 

High-strength Ti10V2Fe3Al: Designed for high-load and high-torque scenarios, it is used in precision transmission gears of robots and load-bearing joints of the legs of heavy-duty robots.

 

High-elasticity and low-modulus titanium alloys (e.g., TiNbTa, Ti24Nb4Zr8Sn): Their elastic modulus is closer to that of human bones, with outstanding flexibility and biocompatibility. They are mostly used in bionic joints, flexible actuators and structural components of wearable robots, which can reduce impact and improve motion compliance.

 

 

Ruihang Group mainly produces the raw materials for your precision manufacturing. For more details,please reach us to the email: Sam.Rui@bjrh-titanium.com