Page 62 - 《橡塑技术与装备》英文版2026年2期

HINA R&P TECHNOLOGY AND EQUIPMENT

used in humanoid robots, where it is applied to parts such as As the core material of flexible printed circuits (FPC),
knee joints, elbow joints, and wrist joints, as well as gears, PI is used in control systems and flexible wiring. When
racks, housings, and structural components, to withstand high applied to robot joints, PI enhances signal transmission
loads and frequent impacts. By adding reinforcement materials efficiency and joint response speed, functioning like a robot's
such as carbon fibers, the strength can be further enhanced, nervous system. PI can integrate various sensor circuits for
effectively reducing friction and wear, and improving motion environmental perception and multifunctional integration,
accuracy and lifespan. The lightweight of PEEK helps reduce detecting environmental characteristics such as contact force
the overall load on the robot and lower energy consumption. and vibration, and endowed with conductivity, self-healing,
PEEK has good electrical insulation properties and chemical and other functions through nanocomposite technology.
stability, providing a stable working environment for sensors 2.3 PA
and avoiding the impact of electromagnetic interference and Nylon, scientifically known as polyamide (PA), is a
chemical corrosion on sensor performance. PEEK is widely general term for thermoplastic resins containing repeating
used in the packaging and fixation of components such as amide groups in their molecular backbone. It includes aliphatic
pressure sensors and tactile sensors. PA, aliphatic-aromatic PA, and aromatic PA. Among the five
2.2 PI major engineering plastics, PA is the one with the largest
Polyimide (PI) is a high-molecular polymer with an imide production volume, the most varieties, and the widest range
structure in its main chain. Most high-performance PI main of applications. PA possesses characteristics such as high
chains primarily consist of aromatic and heterocyclic structural mechanical strength, good toughness, high tensile strength,
units. PI boasts the highest flame retardant rating, excellent low friction coefficient, good wear resistance, excellent self-
electrical insulation properties, mechanical properties, lubricity, and good thermal properties. These properties meet
chemical stability, aging resistance, and radiation resistance. the requirements for lightweight, mechanical performance,
With a dielectric constant of 3.4 and a dielectric loss of only and wear resistance of humanoid robots. With its diverse
10-3, it belongs to Class F to H insulation. Its use temperature properties, PA has potential applications in core components
range remains unchanged within -269 to 400 ℃, earning it the such as joints, structural parts, and casings.
reputation as "one of the most promising engineering plastics 2.3.1 PA66
of the 21st century". PA66 (polyamide 66) has become one of the preferred
PI is widely used in humanoid robot applications. materials for high-load components of humanoid robots due
While ensuring strength, PI has a slightly higher density than to its excellent mechanical properties and high temperature
PEEK but with 40% higher strength, making it suitable for resistance. With a density of approximately 1.14g/cm³, it can
lightweight structural components. This allows the mechanical reduce the overall weight to enhance movement flexibility and
arm wall thickness to be reduced to 0.8mm, resulting in energy efficiency. Its tensile strength reaches 70~120MPa,
an overall weight reduction of 25%. As a flexible substrate ensuring structural stability. PA66 is used for joints and
material, PI can be combined with carbon nanotubes, graphene, robotic arm skeletons that undergo frequent movement, and
etc. for flexible sensors and electronic skin, which can integrate is reinforced with glass fibers to improve wear resistance and
sensors for pressure, temperature, humidity, etc., enhancing the prolong service life. With a melting point of about 260 ℃ and a
robot's ability to perceive subtle changes in the environment. heat distortion temperature exceeding 262 ℃, PA66 is suitable
PI can be used at a long-term operating temperature of 300°C for high temperature environments and easy to process. It can
and has a low friction coefficient of 0.17~0.25, meaning that be used with a woven nylon shell to achieve a combination of
under high-temperature loads, its wear is only one-third of that lightweight and impact resistance.
of traditional PEEK materials. It can be used for joints and gear 2.3.2 PA612
components, extending the maintenance cycle of joints from PA612 possesses characteristics such as flexibility,
600 hours to 2,000 hours. self-lubricity, and chemical resistance, and is primarily

·18· Vol.52，No.2