Earbuds Assembly: Robots for Tiny Audio Parts and ABB

A first-generation AirPod weighs about 4 grams and still holds two microphones, a chip and a 93 milliwatt hour battery in its stem. Earbuds assembly means gluing, fitting and testing parts that small by the million, and some robots are now designed for exactly that work. This post goes from headsets built by hand in a Utah kitchen to transistor radio earpieces and the Walkman, then to the wireless earbud boom, the Chinese factories that ship tens of thousands of sets a day, the small ABB robots aimed at wearables, and the open problems.

Fifth-generation AirPods in their charging case, September 2026. Photo: Cheeseburgahhh / Wikimedia Commons (CC BY-SA 4.0)

How headphones were made by hand

Headphones started as tools for radio and telephone operators. The Holtzer-Cabot Company made them for wireless operators in 1909. In 1910 Nathaniel Baldwin in Utah invented a more sensitive telephone receiver, and his first headsets were made by hand in his kitchen. The US Navy tested them and ordered 100, and a manufacturing facility was set up in Utah to fill the orders. These early sets used voice coils wound around the poles of a permanent magnet next to a flexible steel diaphragm. Baldwin's own company, founded in East Millcreek in 1914, peaked at 150 employees and $2 million in yearly sales in the 1920s.

A social club in Atlanta holds a radiophone dance in May 1920, with dancers wearing earphones to hear a band playing across town. Photo: unknown author via Wikimedia Commons (public domain)

Consumer headphones came in the 1950s. John C. Koss, a jazz musician from Milwaukee, produced the first stereo headphones in 1958. Small earpieces that sit in the ear canal were first developed for hearing aids and spread with transistor radios after the Regency TR-1 went on sale in 1954; about 150,000 TR-1s were sold. Then Sony's Walkman TPS-L2 arrived on 1 July 1979. Sony expected to sell about 5,000 a month and sold more than 30,000 in the first two months, and about 220 million cassette Walkmans were sold before production ended in 2010.

A Sony Walkman TPS-L2, the cassette player that went on sale in Japan on 1 July 1979. Photo: Anna Gerdén / Wikimedia Commons (CC BY-SA 3.0)

Robots built for small electronics came later. ABB introduced the world's first microprocessor-controlled, all-electric industrial robot in 1974, and on 13 April 2015 it introduced YuMi, a dual-arm robot designed for the consumer electronics industry, with flexible hands, camera-based part location and lead-through programming. ABB said demand for electronics had outrun the supply of skilled labor. Integrators then put YuMi on fiddly jobs. Components with wire legs were usually inserted into circuit boards by hand, and capacitors can arrive in bulk or in wobbly foil blisters, yet for GLAUB Automation & Engineering a YuMi now fits them into boards and checks its own work.

An ABB YuMi fitting through-hole components into a circuit board in a cell built by GLAUB Automation & Engineering. Photo: ABB

Wireless earbuds and the factories behind them

Wireless earbuds made headphones an electronics product built in very large numbers. Apple announced AirPods on 7 September 2016 and began taking orders on 13 December, and within two years they were Apple's most popular accessory. Their charging case holds a 1.52 watt hour battery that tops up the tiny cells in the stems. Luxshare Precision, founded in Shenzhen in 2004 by Wang Laichun and her brother, began assembling AirPods in 2017 and became the world's largest maker of the earbuds, VnExpress reported on 7 October 2026. Apple announced AirPods 5 on 9 September 2026.

Apple AirPods and their charging case, photographed on the day of their announcement in September 2016. Photo: Maurizio Pesce / Wikimedia Commons (CC BY 2.0)

One county now ships earbuds on an industrial scale. On 23 September 2026 People's Daily described the Ji'an High-Tech Industrial Development Zone in Jiangxi as the world's largest production base for high-end wireless Bluetooth earbuds. In the smart workshop of Jiangxi Luxshare Intelligent Manufacture, 17 production lines were running at full capacity, and tens of thousands of sets of earbuds left every day. The county's audiovisual equipment cluster had output of more than 30 billion yuan in 2025, and its companies, 27 of them national-level high-tech enterprises, have spent more than 1.1 billion yuan on research over the past three years.

A pair of Xiaomi wireless earbuds and their case taken apart, showing the tiny batteries and circuit boards inside. Photo: Dmitry G / Wikimedia Commons (CC BY-SA 3.0)

ABB has a robot designed for this scale of part. In October 2022 it launched the IRB 1010, its smallest industrial robot, for wearable devices including smart watches, earphones, sensors and health trackers. It has a 370 mm reach, a 135 by 250 mm footprint and a 1.5 kg payload, and ABB lists film peeling, material handling, assembly, gluing and inspection among its jobs. Its OmniCore E10 controller gives position and path repeatability of 0.01 mm. We found no named earbud maker using it, so its place on an earbud line is a possibility.

ABB's IRB 1010, its smallest industrial robot, held in two hands. ABB built it for wearables such as smart watches and earphones. Photo: ABB

Where earbuds assembly goes next

At home, the big issue is repair. Lithium-ion batteries in AirPods degrade, and two-year-old sets can last less than half of the advertised five hours. Apple replaces batteries and individual earbuds, but AirPods cannot be repaired without destroying their outer case, and iFixit gave the first, second and fourth generations a repairability score of 0 out of 10. Earbuds designed to be opened again would change how they are put together. Factories face a different pressure: ABB notes that the demand for new devices forces electronics makers to keep changing their production lines.

AirPods Pro (2nd generation) earbuds next to their charging case. Photo: Hajoon0102 / Wikimedia Commons (CC BY-SA 4.0)

ABB sells its electronics robots on flexibility. They can be reprogrammed for a new model, and ABB says simulation in RobotStudio lets a company build and test a robot cell as a digital twin before touching the real line. For earbuds, that could mean an IRB 1010 dispensing glue or peeling film in a dense cell, with a YuMi beside it fitting parts that need two hands. ABB already sells YuMi for work alongside people, as in the GLAUB cell. Our post on smartwatch assembly covers a similar wrist-sized line. These are possibilities, since we found no ABB earbud project.

The YuMi cell at GLAUB placing components into circuit boards on a conveyor. Photo: ABB

The open problems are precision, jobs and cost. ABB notes that high component density and tiny, delicate parts demand great precision during assembly. Automation also changes who works in these zones: at Eaglerise's transformer plant in the same Ji'an zone, more than 100 robot arms help 180 people produce what 600 once did. A robot cell also has to earn back its cost across model changes. ABB's answer for the IRB 1010 is density: its small footprint lets more cells fit into the same floor space. Luxshare's founder, Wang Laichun, started out herself as an assembly-line worker at Foxconn in 1988.

The inside of an original 1979 Sony TPS-L2 Walkman, opened up for a teardown. Photo: Dave Jones / Wikimedia Commons (CC BY 2.0)

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