PHYBOT C1
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Last reviewed
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| Developer | PHYBOT (Beijing Phybot Technology Co., Ltd.) |
| Type | Compact humanoid robot |
| Country of origin | China |
| Unveiled | 2025 |
| Height | 128 cm (4 ft 2 in) |
| Weight | 28 kg (62 lb) |
| Degrees of Freedom | 25+ |
| Battery | Removable; 4+ hours runtime |
| Max Joint Torque | 244 N·m |
| Arm Payload | 5 kg per arm |
| Back Payload | 20 kg |
| Actuators | Cycloidal gear actuators |
| Special Features | HD projection module, breathing light strip, imaging module |
| Target Applications | Home, education, elderly care, retail, museums |
| Website | phybot.tech |
PHYBOT C1 is a compact humanoid robot developed by Beijing Phybot Technology Co., Ltd. (PHYBOT), a Chinese robotics startup founded by Tsinghua University alumni. Standing 128 cm (4 feet 2 inches) tall and weighing 28 kg (62 pounds), the C1 is designed for social interaction, companionship, and light-duty assistance in indoor environments such as homes, classrooms, shopping malls, and museums. It is the smaller, service-oriented counterpart to the company's flagship PHYBOT M1, a full-size humanoid built for industrial and physically demanding tasks.[1][2][3]
The C1 is notable for being one of the first compact humanoid robots to incorporate cycloidal drive actuators, a type of gear mechanism typically reserved for heavy-duty industrial robots. This technology, derived from PHYBOT's proprietary PhyArc actuator line, gives the C1 a maximum joint torque of 244 N·m and enables it to lift and manipulate loads that are disproportionately large relative to its small frame. The robot also features an advanced imaging module for multimodal interaction, an HD projection system, and a dynamic breathing light strip that conveys emotional feedback, making it one of the more expressive humanoid platforms in its size class.[1][4][5]
PHYBOT was established in September 2024 by Ren Xiaoyu (CEO) and Mao Shuhan, who were roommates in the mechanical engineering program at Tsinghua University in Beijing. Before founding PHYBOT, Ren worked on humanoid robot algorithms at UBTECH Robotics in Shenzhen and served as a senior motion control engineer at Fourier Intelligence in Shanghai, giving him direct experience with two of China's most prominent humanoid robotics firms. Mao Shuhan holds dual degrees in engineering and finance and brings investment banking experience to the company's business operations.[6][7]
The company operates under the motto "Robot for AI," reflecting a belief that physical robotic hardware is essential for bridging the gap between cognitive artificial intelligence and embodied intelligence. PHYBOT's approach combines what it calls a "General Motion Control Model" with custom hardware design, aiming to create robots that can learn and adapt to real-world physical tasks rather than operating purely from pre-programmed routines.[8]
In January 2026, PHYBOT completed a billion-level Angel++ financing round totaling over 200 million yuan (approximately $28 million USD). The company announced plans to deploy the capital toward accelerating development of its general-purpose humanoid robots and core joint module technologies, advancing commercialization across multiple application scenarios, and expanding its global presence.[8]
For a more detailed account of the company's history, founding team, and corporate vision, see PHYBOT M1.
The C1 was designed to fill a different market niche than PHYBOT's full-size M1. Where the M1 is built for physically demanding industrial tasks, heavy lifting, and dynamic maneuvers such as backflips, the C1 prioritizes approachability, safe indoor operation, and multimodal interaction with people. The robot's compact 128 cm stature places it at roughly the height of a young child, which PHYBOT intentionally chose to make the robot feel non-threatening and approachable in environments where it operates alongside humans, particularly children and elderly individuals.[1][2]
The exterior of the C1 uses skin-friendly materials with a welcoming aesthetic designed for comfort in close-contact settings such as homes, classrooms, and retail spaces. Unlike the M1's titanium and aluminum alloy frame optimized for structural strength and impact resistance, the C1 uses a composite polymer and aluminum construction that keeps the robot lightweight at 28 kg while providing adequate durability for indoor service environments.[1][2][3]
PHYBOT also designed the C1 as an accessible development platform for embodied AI research. Its simple mechanical structure gives developers an easy way to test locomotion, perception, and basic object handling on real hardware rather than relying solely on simulation. Researchers can integrate computer vision models, path-planning algorithms, and speech-based interaction systems, and the C1 responds reliably to real-time commands. This positions the C1 as a bridge between desktop research robots and full-size industrial humanoids.[3][5]
The C1 stands 128 cm (4 feet 2 inches) tall and weighs 28 kg (62 pounds), making it significantly smaller and lighter than the M1's 172 cm height and sub-60 kg weight. The robot features a bipedal humanoid form factor with two arms, two legs, and a head unit that houses its imaging and projection systems. The construction combines composite polymer materials for the exterior shell with aluminum structural elements, balancing lightness with structural integrity.[1][2]
The robot has 25 or more degrees of freedom distributed across its body, enabling fluid, lifelike motion. Each arm provides enough articulation for basic manipulation tasks such as grasping handles, carrying objects, and interacting with common tools or devices. Each hand features five fingers, supporting tasks that require a degree of dexterity, though the C1's manipulation capability is oriented toward light-duty service tasks rather than the heavy industrial handling that the M1 targets.[1][2][4]
| Parameter | Value |
|---|---|
| Height | 128 cm (4 ft 2 in) |
| Weight | 28 kg (62 lb) |
| Construction material | Composite polymer + aluminum |
| Total degrees of freedom | 25+ |
| Fingers per hand | 5 |
| Maximum joint torque | 244 N·m |
| Arm payload capacity | 5 kg per arm |
| Back payload capacity | 20 kg |
| Locomotion | Bipedal (walking) |
| Battery type | Removable, modular quick-swap |
| Battery life | 4+ hours |
| Actuator type | Cycloidal gear actuators |
| Special modules | HD projection, imaging, breathing light strip |
| Connectivity | Bluetooth, WiFi |
| LLM integration | Yes |
| Operating system | Linux/ROS |
| ROS compatible | Yes |
| Target environments | Indoor (home, retail, education, healthcare) |
The defining technology of the PHYBOT C1, shared with the larger M1, is its use of cycloidal drive actuators rather than the harmonic drives found in the majority of humanoid robots on the market. Cycloidal drives transfer motion by distributing forces across multiple rolling contact points rather than relying on a single gear tooth. This design provides several advantages for a service humanoid that must operate continuously in real-world environments.[4][5][9]
The C1 is one of the first compact humanoid robots to incorporate cycloidal gear technology, which is typically found only in larger industrial robot systems. This choice reflects PHYBOT's strategy of applying its core PhyArc actuator technology across its entire product lineup, from the heavy-duty M1 to the service-oriented C1. The cycloidal actuators in the C1 achieve a maximum joint torque of 244 N·m, which is remarkable for a robot of its size and allows it to lift and move loads disproportionate to its compact frame.[4][5]
Key advantages of cycloidal drives in the C1 include:
The tradeoff is that cycloidal drives have not yet been validated by the broader market for humanoid applications at this scale. Harmonic drives remain the industry standard for most humanoid robots due to their proven track record and extremely low backlash. PHYBOT's decision to use cycloidal technology in the compact C1 is a bet that the advantages in durability, torque density, and shock resistance will outweigh the risks of adopting a less established approach in the service robotics segment.[9]
The C1 incorporates several features designed specifically for human interaction that distinguish it from research-oriented compact humanoids:
These interactive capabilities set the C1 apart from many compact humanoids that focus primarily on locomotion and manipulation research. The combination of projection, imaging, and expressive lighting positions the C1 as a platform for exploring human-robot interaction in social and commercial settings.
The C1 operates on a removable battery system that provides more than 4 hours of continuous operation. The battery supports modular quick-swap replacement, enabling near-continuous operation in busy commercial environments such as shopping malls, museums, and care facilities. When the battery runs low, an operator can swap in a freshly charged unit without shutting down the robot for extended charging periods.[1][2]
The 4-hour runtime is roughly double that of the larger M1, which provides 2 or more hours on its dual 9 Ah swappable battery system. The C1's longer endurance reflects both its lower power demands (due to its smaller size and lighter weight) and the requirements of its target deployment environments, where sustained operation throughout business hours is essential.[1][6]
The C1 and M1 represent two complementary approaches within PHYBOT's product strategy. The M1 is a full-size, high-performance humanoid designed for industrial environments, logistics, and disaster response, while the C1 is a compact, interaction-focused platform for service, education, and companion applications. Both share PHYBOT's core cycloidal actuator technology but apply it to very different use cases.
| Feature | PHYBOT C1 | PHYBOT M1 |
|---|---|---|
| Height | 128 cm (4 ft 2 in) | 172 cm (5 ft 8 in) |
| Weight | 28 kg (62 lb) | <60 kg (132 lb) |
| Degrees of freedom | 25+ | 32 |
| DOF per hand | 5 fingers | 5 fingers (6 DOF) |
| Maximum joint torque | 244 N·m | 530 N·m |
| Torque density | Not disclosed | 200 N·m/kg |
| Arm payload | 5 kg per arm | 10 to 20 kg |
| Back payload | 20 kg | 50+ kg |
| Walking speed | Moderate (indoor pace) | 1.4 m/s (5.0 km/h) |
| Running capability | No | Yes (2.8 m/s / 10.1 km/h) |
| Backflip capability | No | Yes |
| Battery life | 4+ hours | 2+ hours |
| Battery system | Removable, quick-swap | Dual 9 Ah swappable, 72 V |
| Construction | Composite polymer + aluminum | Titanium + aluminum alloy |
| Actuator type | Cycloidal gear | PhyArc cycloidal drives |
| Compute | Not disclosed | NVIDIA Jetson Orin + Intel Core i7 |
| Sensors | Imaging module, depth cameras | 3D LiDAR, stereo RGB, IMU |
| Special features | HD projection, breathing light strip | Modular backpack system |
| Primary applications | Home, education, elderly care, retail | Industrial, logistics, disaster response |
| Target price | Approximately $22,000 | Under $42,000 |
The comparison illustrates how PHYBOT tailored each robot to its intended operating environment. The M1's 530 N·m peak torque and 50+ kg backpack capacity make it suitable for material handling and construction, while the C1's 244 N·m torque and 5 kg arm payload are calibrated for light manipulation tasks such as carrying a tray, handing over a document, or guiding a user through an interactive display. The C1's 4-hour battery life addresses the need for sustained operation in commercial service roles, while the M1's 2-hour runtime reflects the higher power demands of heavy-duty physical work.[1][6]
PHYBOT has positioned the C1 for deployment across several domains where approachable, interactive robotics can enhance daily experiences:
The C1's HD projection module and imaging system make it a natural fit for educational environments. In classrooms and training facilities, the robot can display instructional content, guide students through interactive lessons, and serve as a hands-on platform for robotics and AI curricula. Its compact size and welcoming design make it appropriate for use around children without causing intimidation. For university robotics programs, the C1 also serves as a development platform where students can implement and test computer vision, natural language processing, and locomotion algorithms on real hardware.[1][3]
The C1 is designed for social interaction and companionship roles in elderly care settings. The robot can provide routine assistance, deliver reminders, and engage elderly residents in conversation or guided activities. Its emotional expression capabilities through the breathing light strip and responsive imaging module help create a sense of presence and engagement that purely functional robots lack. The 4-hour battery life with quick-swap support enables the C1 to remain active throughout care facility operating hours.[2][3]
In shopping mall and retail environments, the C1 can serve as a customer service assistant, greeting visitors, providing directions, and presenting product information through its projection system. The robot's ability to navigate indoor spaces, recognize people, and respond to natural interaction makes it suitable for customer-facing roles. Several Chinese robotics companies, including UBTECH Robotics and Keenon Robotics, have deployed similar service robots in retail settings, and the C1 enters this market with the added differentiation of its cycloidal actuator technology and projection capabilities.[2][3]
Museum tours represent another target application for the C1. The robot can guide visitors through exhibits, projecting supplementary visual content and providing narrated explanations. Its compact form factor allows it to move through gallery spaces without blocking sightlines, while its interactive imaging module enables it to respond to visitor questions and adapt its presentation based on audience engagement.[2][3]
Beyond commercial service applications, the C1 functions as an affordable development platform for embodied AI research. Its simple structure and ROS compatibility give researchers an accessible way to test locomotion algorithms, perception systems, and human-robot interaction models on physical hardware. The robot bridges the gap between desktop research platforms and full-size industrial humanoids, offering a middle ground for laboratories that need real-world testing capability without the cost and complexity of larger systems.[3][5]
The PHYBOT C1 enters the compact humanoid and service robot market at a time when multiple companies are developing platforms for similar applications. The following table compares the C1 with several notable competitors in the compact humanoid segment.
| Company | Robot | Height | Weight | DOF | Key Differentiator | Approximate Price |
|---|---|---|---|---|---|---|
| PHYBOT | C1 | 128 cm | 28 kg | 25+ | Cycloidal actuators, HD projection | ~$22,000 |
| Unitree Robotics | G1 | 127 cm | 35 kg | Up to 43 | Low cost, high DOF, open ecosystem | ~$16,000 |
| Unitree Robotics | R1 | 123 cm | 29 kg | 31 | Ultra-low cost, cartwheel capable | ~$4,900 |
| Fourier Intelligence | GR-1 | 165 cm | 55 kg | 40 | Healthcare focus, rehabilitation heritage | ~$150,000 (est.) |
| UBTECH Robotics | Walker S2 | 140 cm | 49 kg | 42 | Mass production, automotive deployment | Not public |
| Keenon Robotics | XMan R1 | 170 cm | N/A | 36 | Hospitality integration, bartending | ~$100,000 |
The C1's most direct competitor in terms of size and price is the Unitree G1, which stands at a nearly identical 127 cm and offers up to 43 degrees of freedom at a lower price point of approximately $16,000. The G1 benefits from Unitree's established developer community and high production volumes (Unitree shipped approximately 5,500 humanoid units in 2025 and targets 20,000 in 2026). However, the G1 uses standard electric motors rather than cycloidal drives, and it lacks the C1's dedicated projection and imaging modules for interactive service applications.[10][11]
The Unitree R1, launched in early 2026 at roughly $4,900, represents the most aggressive price competition in the compact humanoid space. At 123 cm tall and 29 kg, its dimensions closely match the C1, though it is positioned primarily as a research and development platform rather than a commercial service robot.[11]
The C1 differentiates itself through two primary advantages. First, its cycloidal actuator technology provides higher torque output (244 N·m) relative to its size than most competitors using harmonic or planetary gear drives, giving it a mechanical advantage for manipulation tasks. Second, its integrated projection and imaging systems are purpose-built for interactive service scenarios, whereas many competing platforms require third-party add-ons to achieve similar multimodal interaction capabilities.[4][5]
The C1 is one of several robots in PHYBOT's growing product portfolio. The company applies its core PhyArc cycloidal actuator technology across multiple form factors and market segments.
| Product | Type | Description |
|---|---|---|
| PHYBOT M1 | Full-size bipedal humanoid | 172 cm, 32 DOF, 530 N·m torque; designed for industrial, logistics, and disaster response applications. Known for performing a standing backflip. Target price under $42,000. |
| PHYBOT C1 | Compact bipedal humanoid | 128 cm, 25+ DOF, 244 N·m torque; designed for home, education, elderly care, and retail service. Features HD projection and breathing light strip. |
| PHYBOT C2 | Agile service robot | An agile robot designed specifically for commercial service environments. Details not yet fully disclosed. |
| PHYBOT D1 | Four-wheeled-foot robot | A modular robot combining passenger and cargo transport capabilities with the ability to navigate extreme terrain. Each biped section weighs 24.3 kg and can link together to form a quadruped carrying up to 100 kg. Maximum rolling speed of 11 km/h with 5+ hours of runtime. |
This product lineup strategy reflects PHYBOT's ambition to serve the full spectrum of robotics applications, from heavy industrial work (M1) to lightweight service (C1 and C2) to terrain mobility (D1). The common thread across all products is the PhyArc cycloidal actuator technology, which PHYBOT considers its primary technological differentiator.[6][8]
The PHYBOT C1 enters the market during a period of rapid expansion in China's robotics industry, supported by significant government backing and venture capital investment. The Chinese government has identified humanoid robots as a strategic technology and included them in national development plans, driving substantial investment into the sector. In the first half of 2025 alone, $3.1 billion was invested across 61 venture deals in the humanoid robotics sector globally, exceeding the $2.9 billion invested in the entire period from 2010 to 2024.[12][13]
Chinese firms dominate the compact humanoid market by volume. In 2025, Unitree Robotics shipped approximately 5,500 humanoid units, AgiBot shipped 5,168 units, and UBTECH Robotics shipped approximately 1,000 units, with Chinese companies accounting for nearly 90% of global humanoid robot shipments. UBTECH reported orders exceeding 800 million yuan (approximately $112 million) for its Walker series humanoid robots since early 2025, and has begun mass production of the Walker S2 with plans to scale to 5,000 units annually by 2026 and 10,000 by 2027.[14][15]
The service robotics segment, where the C1 competes, is expected to grow substantially as robots move beyond factory floors into retail, healthcare, and hospitality environments. The global humanoid robot market was projected to grow from approximately $2.92 billion in 2025 to $15.26 billion by 2030, representing a compound annual growth rate of 39.2%. The service-oriented segment of this market, encompassing companion robots, educational platforms, and customer service assistants, represents a significant growth opportunity as robots become more capable of natural interaction and sustained autonomous operation.[12][13]
PHYBOT's September 2024 founding and rapid product development timeline, moving from incorporation to multiple product announcements in roughly a year, reflects the intense pace of development in China's humanoid robotics ecosystem. The C1's combination of industrial-grade actuator technology in a compact, interactive form factor represents an attempt to bridge the gap between research platforms and commercially viable service humanoids.[6][7][8]