Sunny Xiaojun Sun is Founder and CEO of BionicM, a Tokyo-based medtech company building powered prosthetic legs with humanoid robotics technology.

Sunny came to Japan in 2009 as an exchange student at Tohoku University, then earned his master's degree at the University of Tokyo and joined Sony as an engineer in 2013. He later completed a PhD in Information Science at the University of Tokyo under the robotics lab of Professor Masayuki Inaba.

Sunny lost his leg at age nine in rural China and used crutches for 15 years before receiving his first prosthetic. That lived experience as an amputee shapes BionicM's user-driven design approach.

BionicM spun out of the University of Tokyo in December 2018 with backing from UTEC and the JST START program. The company recently closed the first tranche of a Series B led by B Dash Ventures and Mitsubishi UFJ Capital.

The Bio Leg earned FDA Class II registration, US insurance coverage approval and a CES 2025 Best of Innovation award. BionicM has raised about 2.58 billion yen in total and plans to launch its ASISTA powered knee in the US in 2027.