A bottle of acid reveals the underlying material chain of high-end manufacturing

1. The industrial chain triggered by a bottle of acid
Since May, South Korean producers of anhydrous hydrofluoric acid have begun sourcing the material from China, with the purchasing price rising by approximately 40% compared to the beginning of the year. This batch of material, after purification, is transformed into electronic-grade hydrofluoric acid, which is supplied to semiconductor companies such as Samsung Electronics and SK Hynix.
Anhydrous hydrofluoric acid sounds remote to ordinary people. In chip manufacturing, it is used for wafer cleaning and etching, and its purity, impurity control, and supply stability directly affect subsequent production.
In the past, when discussing chips, everyone was most interested in lithography machines, advanced packaging, EDA, and computing power chips. Now, with Korean companies' centralized procurement, a more fundamental fact has been revealed. When high-end manufacturing goes deep, what matters most is materials.
The focus of this matter extends beyond semiconductors. Fluorine chemistry starts with fluorspar and hydrofluoric acid, and then extends to electronic chemicals, fluorine-containing polymers, lithium battery materials, pharmaceutical and pesticide intermediates, as well as a range of high-end fluorine-containing fine chemical products. Among these, one name has recently become increasingly associated with robots.

II. PEEK, a candidate material for robot bodies
PEEK, whose Chinese name is polyetheretherketone, is a high-performance engineering plastic. It belongs to a different system from fluoroplastics such as PTFE and PVDF. Its relationship with fluorine chemistry lies in the upstream monomers. In the classic synthesis route of PEEK, common raw materials include 4,4'-difluorobenzophenone and hydroquinone. 4,4'-difluorobenzophenone is a fluorinated aromatic intermediate used in the preparation of high-performance polymers such as PEEK or PAEK.
So this line is very coherent. South Korea's rush to purchase anhydrous hydrofluoric acid first ignited the sentiment for semiconductor materials. Looking down the fluorine chemical industry, we see fluorine-containing fine chemicals. Looking further to high-end materials, we see PEEK. Looking further to terminal applications, robot bodies are emerging.
When it comes to mass-producing humanoid robots, the question shifts from whether they can move to whether they can work for a long time. Every aspect, including weight, strength, friction, fatigue resistance, high temperature resistance, and dimensional stability, needs to be recalculated. A robot may appear to be an AI product, but its body is actually a manufacturing product. Joints need to rotate repeatedly, gears need to mesh for a long time, bearings need to withstand wear, insulating parts need to be stable, sliding parts need to have low friction, the body needs to be lightweight, and the structure needs to be impact-resistant.
PEEK is heat-resistant, wear-resistant, and has high mechanical strength and good dimensional stability, making it more valuable than ordinary engineering plastics in harsh scenarios. In its 2025 annual report, Kingfa Technology mentioned that special engineering plastics such as PEEK and PPS, as well as lightweight modified plastics, have been applied to the joints and body of embodied intelligent robots. This sentence indicates that robot materials have moved from conceptual narratives to specific components.
III. From joints to fingers, the robot's physical battle
In the past, when discussing robots, everyone focused on large models, cameras, algorithms, and computing power. Next, the market will increasingly pay attention to the body of robots. Joint actuators, harmonic reducers, planetary roller screws, coreless motors, bearings, encoders, torque sensors, tactile sensors, flexible skin, wiring harnesses, and connectors will all come into view. AI is responsible for enabling machines to think, while materials and components are responsible for allowing machines to stand up, hold things, and work for a long time. Without these things, robots can only remain in demonstration videos.
Optimus Prime serves as the best reference. In January this year, Musk mentioned Cybercab and Optimus, stating that the initial production pace would be slow due to the novelty of almost everything. The more components and manufacturing steps involved, the harder it is to ramp up production. The report also indicated that production of Optimus is expected to commence around the end of 2026. As humanoid robots move towards mass production, the challenge has shifted from whether they can be built to whether they can be consistently manufactured, cost-effectively produced, and delivered on a large scale.
This is exactly the path that new energy vehicles took back then. When new energy vehicles first gained popularity, everyone focused on the complete vehicle. Later, it was discovered that each layer, including batteries, motors, electronic controls, thermal management, lightweight materials, connectors, and power devices, had its own industrial opportunities. A similar process will also occur for humanoid robots. Initially, it is the complete robot companies that attract attention, followed by joints, hands, motors, reducers, sensors, and then down to magnetic materials, bearings, engineering plastics, carbon fiber, electronic skins, wiring harnesses, and connectors.
IV. Three directions worth tracking
PEEK is just an entry point in this story. The bigger story is that the industrial chain of robot bodies is starting to be re-priced. The next three directions are the easiest to continue to advance.
First, robot joints. Humanoid robots need to walk, bend over, carry, and grasp, and joints determine the quality of their movements. Joints contain motors, reducers, lead screws, bearings, sensors, and also use wear-resistant, lightweight, and high-strength materials.
Second, dexterous hands. If a robot can walk, the audience will be amazed once. If a robot can pick up eggs, twist bottle caps, plug in wires, and sort parts, the audience will continue to pay attention. Behind the dexterous hands are micro-motors, tendon ropes, tactile sensors, flexible materials, and low-friction joints.
Third, the robot material war. PEEK, PPS, PPA, LCP, polyimide, carbon fiber composites, titanium alloy, rare earth permanent magnets, and electronic skin materials will all be rekindled by the mass production of robots.
The more human-like a robot becomes, the more materials it consumes. When Korean companies purchase hydrofluoric acid, it leads to a longer high-end manufacturing chain. From chip cleaning to fluorine-containing fine chemicals, from PEEK to robot joints, dexterous hands, and lightweight bodies. AI is responsible for thinking, while materials are responsible for making the machine stand up. The next wave of robot enthusiasm may not only be in large models. It may well be hidden in the joints, in the fingers, and in a very expensive, lightweight, and wear-resistant material.