Apple has accused a former Apple Watch engineer of stealing confidential sensor technology and giving it to Chinese rival Oppo as it tries to catch up in the smartwatch market. Apple filed a court document with the Northern District Court of California on August 21, 2025, accusing former engineer Chen Shi of stealing trade secrets.

Chen Shi, who worked as a sensor systems architect at Apple from 2020 to 2025, is accused of stealing the information before joining Oppo's Palo Alto-based InnoPeak Technologies.

Apple claims that Chen downloaded 63 confidential documents from the company's secure Box folder in the last few weeks of his tenure at the company and copied them to a USB flash drive before resigning. He also held dozens of one-on-one meetings with colleagues to get information.

The stolen documents allegedly include Apple Watch health technologies such as photoplethysmography (PPG), electrocardiogram (ECG) capabilities, and proprietary temperature sensing methods. Additionally, chip engineering documentation and product roadmaps are included.

The company noted that in an internal chat, Chen Shi told Oppo's VP of Health that he was "gathering as much information as possible from Apple" to share later. Instead of rejecting the plan, the Oppo executive reportedly responded with an "OK" emoji.

Oppo may not be a household name in the United States, but it's a huge player in China's smartphone industry. Oppo entered the smartwatch market in 2020, several years after Apple debuted in the market in 2015.

InnoPeak Technology runs Oppo's U.S. research center in Silicon Valley, which is right in Apple's backyard. Apple alleges Oppo has been using the office as a beachhead to poach Western engineering talent and steal intellectual property.

Apple's complaint cites the 2016 Protection of Trade Secrets Act, which gives companies the power to sue over stolen confidential information. Apple also cited breach of contract because Chen signed a nondisclosure agreement when he joined Apple in 2019.

The plot of this case seems familiar. Apple has faced similar lawsuits in the past, whether it was fighting Masimo in an Apple Watch sensor patent dispute or suing its own former employees as it did in the Rivos chip dispute.

In July 2025, Apple also accused a former Vision Pro engineer of copying confidential documents before joining Snap.

The battle centers on whether employees who leave with knowledge or documentation give competitors an advantage. In a market where innovation is expensive and regulatory approvals are slow, such shortcuts could tip the balance.

Health sensors have become key to Apple's wearables strategy. Since 2018, the Apple Watch has featured an FDA-cleared EKG app, which was later expanded with atrial fibrillation history tracking capabilities.

Apple's temperature sensor and blood oxygen monitoring capabilities enhance its appeal as a health tool. These features make it more than just a digital watch.


Lawsuit highlights importance of health sensors to Apple's wearables strategy

苹果表示，其工程师花费了数年时间完善硬件和算法，以使基于手腕的心脏读数变得可靠，而将这些秘密交给 Oppo 就像是泄露了一份逃避研究费用的蓝图。

Apple’s complaint points to Chen Shi’s leaks. The complaint stated that when Chen was downloading files, he searched online for "how to clear MacBook data" and "how to tell if I have opened files on a shared drive."

Chen Shi also allegedly lied to colleagues about his next move, saying he was leaving to take care of his aging parents rather than jump to Oppo.

These details may have been for juries, but they also underscore the pervasiveness of the problem in Silicon Valley. Engineers not only hold the skills in their heads but also have access to digital information libraries, so the temptation to walk away with these skills is great.

If Apple wins the case, Oppo could be banned from using any technology related to the stolen files, and Chen Shi could face liquidated damages. Apple may also request a forensic audit to find out whether its data was already on Oppo's products.

The lawsuit also touches on geopolitics. Oppo is a unit of BBK Electronics, which owns Vivo and OnePlus, and the lawsuit highlights U.S. concerns about Chinese companies' reliance on U.S. research and development talent to grow rapidly.

Apple Watch has become a market leader by combining health data with consumer technology, and Apple won't allow competitors to cut corners. For Oppo, the lawsuit could become a costly detour in its push for wearables.