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Fourier Intelligence (now operating as Fourier and Fourier Rehab) is a Chinese robotics company headquartered in Shanghai that develops rehabilitation robots and humanoid robots. Founded in 2015 by Alex Gu (Gu Jie) and Zen Koh, the company began as a specialist in robotic exoskeletons for physical rehabilitation and has since expanded into general-purpose humanoid robotics. Fourier's rehabilitation products are deployed in over 2,000 institutions across more than 40 countries, while its GRx series of humanoid robots has positioned the company as one of China's leading humanoid robotics firms alongside Unitree Robotics, UBTECH, and Figure AI.
The company is named after the French mathematician Joseph Fourier. Its official website is fftai.com, and it trades under the brand names Fourier (for humanoid robotics) and Fourier Rehab (for rehabilitation technology) following a corporate rebranding in July 2024.
Fourier Intelligence was founded in 2015 at Shanghai's Zhangjiang Hi-Tech Park by Alex Gu (Gu Jie) and Zen Koh. Gu Jie graduated from Shanghai Jiao Tong University in 2003 with a bachelor's degree in Mechanics. He had been working on robotics research with the university's robotics team since 2002. Before founding Fourier, Gu worked as a sales executive at National Instruments, and in 2012 he founded Jinghe Robot, a startup that developed the Flexbot rehabilitation robot. Jinghe Robot was acquired by rehabilitation device manufacturer QJ Rehab in 2015, and shortly afterward Gu launched Fourier Intelligence.
Zen Koh, the co-founder, brought international healthcare and medical device experience to the company. He previously served as Managing Director of Asia-Pacific operations at Swiss rehabilitation technology company Hocoma, and before that held the role of Assistant Chief Executive of the Singapore National Co-operative Federation. Koh has over 20 years of experience in healthcare solutions and medical devices for people with disabilities. In 2012, he was recognized by MD+DI as one of their "40 under 40 Future Most Influential Industry Leaders in MedTech."
The company's first major product, the Fourier X1, was unveiled at the World Federation for Neuro-Rehabilitation Conference (WFNR) in Shanghai on March 20, 2017. The Fourier X1 was a lower-limb exoskeleton, the first of its type designed for commercial use in mainland China. It featured a battery-powered system with motors at both hip and knee joints. The X1 was designed to be one of the most affordable powered exoskeletons on the market, leveraging Chinese advantages in industrial design and manufacturing cost reduction.
Following the launch of the Fourier X1, the company rapidly expanded its rehabilitation robotics product line. By 2019, Fourier had deployed intelligent rehabilitation devices, including exoskeletons, in hundreds of hospitals and medical care centers across more than 10 countries.
During this period, Fourier developed a comprehensive portfolio of rehabilitation robots covering upper-limb, lower-limb, ankle, wrist, and balance therapy. Products such as the ArmMotus EMU (the world's first 3D back-drivable upper-limb rehabilitation robot), the ExoMotus M4 lower-limb exoskeleton, and specialized devices like the AnkleMotus M1A and WristMotus M1W established the company as a global leader in robotic rehabilitation.
The company also introduced the Fourier RehabHub, an AI-driven robotic platform that integrates multiple specialized rehabilitation robots for neurological, orthopedic, and pain management therapies. Fourier built collaborative relationships with over 30 world-leading hospitals and research institutions to validate and deploy its products.
On July 6, 2023, Fourier Intelligence unveiled the GR-1 general-purpose humanoid robot at the World Artificial Intelligence Conference (WAIC) in Shanghai. The GR-1 attracted significant attention as Fourier claimed it would be one of the first mass-produced general-purpose humanoid robots. The company aimed to manufacture 100 units by the end of 2023 and deliver thousands of units in 2024.
By December 2023, Fourier had achieved its target, with over 100 GR-1 units delivered to companies, universities, and AI research labs across various sectors. These units were primarily intended for research and development purposes, allowing partners to develop and test applications for humanoid platforms.
In July 2024, Fourier Intelligence underwent a strategic rebranding, splitting its operations into two distinct brands: Fourier, focused on humanoid robotics and general-purpose robots, and Fourier Rehab, a dedicated subsidiary for rehabilitation technology. The move reflected the company's dual strategy of pursuing both embodied AI in humanoid form and continued leadership in clinical rehabilitation robotics.
In late September 2024, Fourier launched the GR-2, a next-generation humanoid robot with significantly improved specifications over the GR-1. The GR-2 was taller, heavier, more dexterous, and equipped with double the battery life of its predecessor. The launch was accompanied by the announcement of an updated software development platform and partnerships with NVIDIA for simulation and training.
In January 2025, Fourier closed a Series E funding round worth nearly 800 million yuan (approximately $109 million), led by Prosperity7 Ventures (the venture capital arm of Saudi Aramco), with participation from investors including Guoxin Investment and Peakvest.
In April 2025, Fourier launched the Fourier N1, an open-source humanoid robot standing 1.3 meters tall and weighing 38 kilograms. The N1 was described as China's first verified open-source humanoid robot, with complete hardware designs, assembly guides, CAD files, bills of materials, and foundational control software published on GitHub. The initiative aimed to lower barriers for startups, educational institutions, and hobbyists looking to develop on humanoid platforms.
In August 2025, Fourier unveiled the GR-3, the company's first "care-centric" humanoid robot. Standing 165 cm tall and weighing 71 kg with 55 degrees of freedom, the GR-3 was designed specifically for social care, companionship, and health monitoring rather than industrial tasks. It featured a multimodal perception system combining vision, audio, and touch into a real-time emotional engine, with animated micro-expressions and 31 distributed pressure sensors for touch detection. Fourier priced the GR-3 above 200,000 yuan (roughly $27,500), targeting healthcare institutions and enterprise clients. The GR-3 was later showcased at CES 2026.
Fourier's humanoid robotics division develops the GRx series of general-purpose humanoid robots. All models in the series use the company's proprietary Fourier Smart Actuator (FSA) technology, which integrates the motor, driver, reducer, and encoder into a single compact module.
| Model | Announced | Height | Weight | Degrees of Freedom | Walking Speed | Peak Torque | Battery Life | Key Features |
|---|---|---|---|---|---|---|---|---|
| GR-1 | July 2023 | 165 cm | 55 kg | 44 | 5 km/h | 230 N.m | Not disclosed | FSA actuators, RealSense camera, pure vision solution with 6 RGB cameras, 11-DoF hands |
| GR-2 | September 2024 | 175 cm | 63 kg | 53 | 5 km/h | 380 N.m | 2 hours | FSA 2.0 actuators (7 types), 12-DoF dexterous hands, 6 array-type tactile sensors, dual-encoder system |
| GR-3 | August 2025 | 165 cm | 71 kg | 55 | Not disclosed | Not disclosed | ~3 hours (hot-swappable) | Care-centric design, multimodal emotional engine, 31 pressure sensors, facial recognition, micro-expressions |
| N1 (open source) | April 2025 | 130 cm | 38 kg | 23 | 3.5 m/s (max running) | Not disclosed | 2+ hours | Fully open-source (hardware + software), FSA 2.0 actuators, aluminum alloy and engineering plastics frame |
The GR-1 was Fourier's first general-purpose humanoid robot. Standing 165 cm tall and weighing 55 kg, it was designed to carry loads of up to 50 kg, nearly its own body weight. The robot features 44 joints, a hip joint module capable of 230 N.m peak torque, and hands with 11 degrees of freedom for grasping cylindrical and round objects. The GR-1 uses a pure vision solution that integrates BEV (Bird's Eye View), Transformer, and Occupancy Network technologies, processing input from six RGB cameras for real-time 3D environmental mapping.
Fourier equipped the GR-1 with natural language processing capabilities comparable to ChatGPT, allowing it to understand and respond to voice commands. More than 100 units were produced and delivered by the end of 2023, primarily to research institutions and technology companies.
The GR-2 represents a significant upgrade over its predecessor. It stands 175 cm tall, weighs 63 kg, and features 53 degrees of freedom. The robot's FSA 2.0 actuator system delivers peak torques exceeding 380 N.m, with a dual-encoder system that doubles control accuracy compared to the GR-1. Seven distinct types of FSA actuators are tailored to meet the specific torque demands of each joint.
The GR-2's hands feature 12 degrees of freedom, doubling the dexterity of the GR-1's hands, and are equipped with six array-type tactile sensors that enable force detection, material identification, and real-time grip adjustment. The battery capacity was doubled, allowing for two hours of continuous operation.
Fourier developed the GR-2 in collaboration with NVIDIA, using NVIDIA Isaac Gym for simulation-based training. During development, the team completed 3,000 training iterations in approximately 15 hours for a floor-to-stand maneuver, and the trained model achieved an 89% success rate when transferred directly to the physical robot. The GR-2's software development kit (SDK) supports ROS, NVIDIA Isaac Lab, and MuJoCo, giving developers access to pre-optimized modules for machine vision, path planning, and force feedback control.
The GR-3 diverges from the general-purpose design of its predecessors by focusing on social care and companionship. It is Fourier's first humanoid designed specifically for interactive roles in nursing homes, rehabilitation centers, and home environments. The robot integrates a "Full-Perception Multimodal Interaction System" that unifies vision, audio, and touch into a real-time emotional engine. Its visual recognition system uses RGB and structured-light camera modules for facial recognition and dynamic tracking, while 31 distributed pressure sensors enable real-time touch detection.
The GR-3 uses a dual-path response architecture: a fast-reflex path for immediate cues and a large language model reasoning path for contextual dialogue. An attention management layer coordinates these pathways to produce smooth, natural behavior. The robot supports emotion recognition, natural dialogue, health monitoring, and rehabilitation assistance.
The Fourier N1 is an open-source humanoid robot released as part of the company's "Nexus Open Source Ecosystem Matrix" project. Standing 1.3 meters tall and weighing 38 kilograms, it has 23 degrees of freedom and achieves a maximum running speed of 3.5 meters per second. The N1 uses proprietary FSA 2.0 actuators and a frame made of aluminum alloy and engineering plastics.
All hardware designs, CAD files, bills of materials, assembly instructions, and basic operating software are publicly available on GitHub. The N1 underwent over 1,000 hours of outdoor testing to validate complex terrain mobility before release.
Fourier Rehab offers a comprehensive portfolio of rehabilitation robots and devices for clinical and institutional use. The product line covers upper-limb, lower-limb, ankle, wrist, and balance rehabilitation.
| Product | Category | Description |
|---|---|---|
| ExoMotus M4 | Lower-limb exoskeleton | Institutional powered exoskeleton for walking retraining; supports passive to assistive therapy modes; used for stroke, spinal cord injury, multiple sclerosis, and other neuromotor conditions |
| ArmMotus EMU | Upper-limb rehabilitation | World's first 3D back-drivable upper-limb robot; cable-driven mechanism with carbon fiber rods; force feedback simulates therapist's hand; supports sitting and standing training |
| ArmMotus M2 Pro | Upper-limb rehabilitation | Advanced arm rehabilitation device for upper extremity recovery with enhanced precision |
| AnkleMotus M1A | Ankle rehabilitation | Specialized device for foot and ankle recovery therapy |
| WristMotus M1W | Wrist rehabilitation | Targeted robot for hand and wrist therapy and range-of-motion training |
| PelmaMotus | Foot rehabilitation | Plantar support and foot-focused rehabilitation device |
| CycleMotus Series | Lower-body exercise | Cycling-based rehabilitation systems for lower body conditioning |
| Fortis Series | Mobility training | Exoskeleton line for patient mobility and strength building |
| OTParvos | Occupational therapy | Movement rehabilitation system for occupational therapy applications |
| EXOPS | Exoskeleton support | Operational exoskeleton system for rehabilitation support |
All of these products integrate into the Fourier RehabHub, an AI-driven platform that unifies Fourier's full range of robotic systems. The RehabHub supports patients through every stage of recovery across neurological, orthopedic, and pain management therapies, using data analytics and AI to personalize treatment plans.
The Fourier Smart Actuator (FSA) is the company's proprietary actuator technology, developed in-house. The FSA integrates the motor, driver, reducer, and encoder into a single compact module, significantly reducing hardware size compared to traditional servo systems while improving performance reliability. The FSA platform powers both Fourier's humanoid robots and its rehabilitation exoskeletons.
The second generation, FSA 2.0, was introduced with the GR-2 and features seven distinct actuator variants tailored to different joint requirements. The dual-encoder design doubles control accuracy, and peak torques exceed 380 N.m. FSA 2.0 actuators are also used in the Fourier N1 open-source platform.
Fourier uses NVIDIA Isaac Gym and NVIDIA Isaac Lab for simulation-based reinforcement learning to train its humanoid robots. By simulating real-world conditions in parallel virtual environments, the company can reduce physical testing time and accelerate the development of locomotion, manipulation, and interaction skills.
The company also leverages NVIDIA TensorRT and CUDA libraries to reduce model training times and improve simulation accuracy. Fourier's robots support integration with frameworks such as ROS, MuJoCo, and NVIDIA Isaac Lab, allowing third-party developers to build applications on the GRx platform.
For perception, the GR-1 and GR-2 use a combination of RGB cameras, RealSense depth cameras, and structured-light modules. The GR-1 employs BEV, Transformer, and Occupancy Network architectures for 3D environmental mapping, while the GR-3 adds a multimodal emotional perception system combining vision, audio, and tactile inputs.
Fourier Intelligence has raised a total of approximately $193 million across multiple funding rounds since its founding in 2015.
| Round | Date | Amount | Lead Investor(s) | Notable Participants |
|---|---|---|---|---|
| Series A | February 2018 | Undisclosed | Not publicly disclosed | IDG Capital |
| Series B | 2019 | Undisclosed | Guozhong Venture Capital | IDG Capital, Volcanics Venture |
| Series C | October 2020 | RMB 100 million (~$14.9M) | Vision Plus Capital | Qianhai FOF |
| Series C+ | July 2021 | Undisclosed | Prosperity7 Ventures | Saudi Aramco-backed |
| Series D | January 2022 | RMB 400 million (~$63M) | SoftBank Vision Fund 2 | Prosperity7 Ventures |
| Series E | January 2025 | Prosperity7 Ventures | Guoxin Investment, Peakvest, Shanghai Zhangjiang |
The Series D round in January 2022, led by SoftBank Vision Fund 2, was particularly significant as it validated Fourier's dual strategy of rehabilitation robotics and humanoid development. The largest round to date, the Series E in January 2025, provided capital to accelerate the development and commercialization of the GR-2, GR-3, and N1 humanoid platforms.
Prosperity7 Ventures, the venture arm of Saudi Aramco, has been a recurring investor across multiple rounds, first participating in the Series C+ round in 2021.
Fourier's business model is distinctive among humanoid robotics companies because it generates substantial revenue from its established rehabilitation robotics division. This revenue stream funds the company's humanoid robotics research and development, reducing its dependence on venture capital alone.
In 2023, overseas revenue from Fourier's rehabilitation division surged more than 50%, accounting for roughly 10% of total revenue. The rehabilitation products are deployed in over 2,000 institutions across more than 50 countries, including the United States, the United Kingdom, Germany, Singapore, Malaysia, Thailand, Australia, Indonesia, South Korea, and the United Arab Emirates.
The 2024 rebranding into Fourier (humanoids) and Fourier Rehab (rehabilitation) formalized this dual-track approach. Fourier Rehab operates as a specialized subsidiary under the Fourier Group, with its own dedicated team and product development pipeline. Zen Koh serves as CEO of the global hub based in Singapore, overseeing international operations for the rehabilitation business.
Fourier's 10th anniversary in 2025 marked an important strategic milestone. The company publicly stated its aim to introduce humanoid robots into health and rehabilitation care scenarios, bridging its two business lines. The GR-3 care-bot is a direct product of this convergence, applying Fourier's deep knowledge of human biomechanics, clinical rehabilitation, and safe human-robot interaction to a humanoid form factor designed for eldercare and clinical settings.
Fourier operates in both the rehabilitation robotics market and the increasingly competitive humanoid robotics sector.
In rehabilitation robotics, Fourier competes with established companies such as Hocoma (now part of DIH), Ekso Bionics, ReWalk Robotics, and Cyberdyne. Fourier's competitive advantage in this market is its comprehensive product portfolio, its AI-driven RehabHub platform, and its strong presence in Asian and emerging markets.
In humanoid robotics, Fourier faces competition from a growing number of Chinese and international companies:
| Company | Country | Notable Humanoid | Market Focus |
|---|---|---|---|
| Fourier | China | GR-2, GR-3 | Rehabilitation, healthcare, research |
| Unitree Robotics | China | G1, H1 | Research, affordable platforms |
| UBTECH | China | Walker S2 | Industrial (Foxconn), commercial service |
| Tesla | United States | Optimus | Manufacturing, household tasks |
| Figure AI | United States | Figure 02 | Warehouse logistics, general purpose |
| Boston Dynamics | United States | Atlas | Research, industrial |
| Apptronik | United States | Apollo | Logistics, manufacturing |
| Sanctuary AI | Canada | Phoenix | General purpose, cognitive AI |
Fourier differentiates itself through its rehabilitation robotics heritage, which gives the company deep expertise in human biomechanics and safe human-robot interaction at a clinical level. This knowledge base is difficult for pure-play humanoid robotics companies to replicate. The company's approach of channeling rehabilitation revenue into humanoid R&D also provides a more sustainable funding model than competitors who rely solely on venture capital.
Among Chinese competitors, Unitree has gained attention for its affordability (the G1 starts at approximately $13,500) and strong SDK, while UBTECH has focused on large-scale industrial deployments. Fourier's niche centers on healthcare, eldercare, and research applications where its rehabilitation background provides a natural advantage.
Fourier operates a network of offices and subsidiaries globally. The company's R&D headquarters is in Shanghai's Zhangjiang Hi-Tech Park, with a global business hub in Singapore. Zen Koh leads the Singapore-based international operations. The company employs approximately 500 people and has presence in over 50 countries through direct offices, distributors, and clinical partnerships.
The Fourier Intelligence Group comprises 12 companies spanning robotics development, rehabilitation technology, and international distribution. Key markets include China, Southeast Asia (Singapore, Malaysia, Thailand, Indonesia), East Asia (South Korea), the Middle East (UAE), Europe (United Kingdom, Germany), and Oceania (Australia).
Fourier has established clinical research partnerships with organizations such as Brooks Rehabilitation in the United States and CUREXO in South Korea. The company regularly exhibits at major industry events including MEDICA (the world's largest medical trade fair in Dusseldorf), RehabWeek, CES, and the World Artificial Intelligence Conference (WAIC) in Shanghai.
| Detail | Information |
|---|---|
| Founded | 2015 |
| Founders | Alex Gu (Gu Jie), Zen Koh |
| Headquarters | Shanghai, China (R&D); Singapore (Global Hub) |
| CEO | Alex Gu (Gu Jie) |
| Co-founder and Deputy Group CEO | Zen Koh |
| Employees | ~500 |
| Website | fftai.com |
| Total Funding | ~$193 million |
| Key Investors | SoftBank Vision Fund 2, Prosperity7 Ventures, Guoxin Investment, IDG Capital |
| Industries | Rehabilitation robotics, humanoid robotics, embodied AI |
| Products | GRx humanoid series (GR-1, GR-2, GR-3, N1), ExoMotus, ArmMotus, RehabHub |