Leading chipmaking engineer Xu Zhenpeng said the United States no longer offered the freedom that researchers once expected – a key reason for his decision to continue his work in China.

Xu, who joined Shanghai Jiao Tong University (SJTU) as a tenure-track assistant professor in January, left behind a team leadership role at Atomic Semi, a California start-up with high-profile backers that included OpenAI’s venture fund.

Before his departure, Xu led a team that was developing a new kind of chipmaking machine using 3D-printed parts that would be smaller, faster and cheaper than today’s large, costly production equipment.

“In my previous role in the semiconductor sector in the US, increasingly strict policies and corporate compliance requirements limited my international mobility, which became a constraint on sustained research development,” he told the South China Morning Post in an email last week.

Xu said his decision to return to China was motivated by long-term academic goals and a desire for a more independent research environment. “Meanwhile, China’s advanced manufacturing research ecosystem is evolving rapidly,” he added.

While Xu did not specify which corporate compliance rules he was referring to, such policies are typically designed to ensure companies follow government restrictions.

In recent years, the US semiconductor sector has come under tighter government export controls, as Washington has sought to prevent advanced chipmaking know-how from strengthening foreign competitors or being used for military purposes.

In practice, compliance restrictions can limit overseas travel, require approval before working with foreign partners or discourage researchers from pursuing certain topics or international collaborations altogether.

Xu said he chose SJTU for its “internationally recognised strength in manufacturing research and close industry ties” – a combination he believed would offer the ideal platform to build his research programme.

In Shanghai, his work will focus on developing high-precision 3D printing for next-generation electronic devices. Xu said he aimed to produce components that combined conductive metals with specialised materials for insulation or sensing, all with micron-level accuracy.

One research direction he intends to pursue involves developing ultra-lightweight antennas for satellites. In a previous study, Xu and his team achieved 3D printed versions 100 times thinner than a human hair, for use in 5G and 6G networks, wearable devices, and compact aerospace systems.

Xu said he planned to refine the process using more advanced materials and fabrication methods to create antennas capable of withstanding extreme environments, including space.

He is also exploring how to simplify chip integration – the step where microchips are connected to other electronic components. Xu’s approach involves 3D-printing the housings with built-in electrical connections in a single step, potentially reducing manufacturing time and costs.