The Robot Studio

The Robot Studio is an independent open-source robotics design studio run by British roboticist Rob Knight, best known for publishing free, buildable designs for anatomically inspired humanoid robots and their hands. Its most widely used release is the DexHand, a low-cost, 3D-printed, tendon-driven dexterous hand intended as a research-and-development platform for humanoid robots. The DexHand V1 has roughly 19 powered degrees of freedom and can be built for about $300 in components if the builder already has access to a 3D printer, which makes it one of the cheapest capable humanoid robot hands available in open source. The design has since progressed through a V2 line, and later self-assembled versions are described by third-party directories as "DexHand V2.3." Note that The Robot Studio's DexHand is unrelated to the commercial "DexHand 021" sold by the Chinese firm DexRobot; they are different products that happen to share a name.^[1][2][8]

At a glance

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The Robot Studio

The Robot Studio is the practice of Rob Knight, a roboticist who has worked on humanoid robots and anthropomorphic hands for roughly two decades.^[10] By his own account he holds two degrees from Cambridge and a master's from Essex, left a PhD after a year, and went on to work as an industrial partner on European Union funded robotics projects, including the anthropomimetic robots CRONOS and ECCERobot in the mid-2000s.^[10] The studio is registered in France and lists an address in the Lyon area.^[4]

The studio's stated goal is to develop "an open-source, general-purpose humanoid robot that can turn its hand to a wide range of tasks."^[4] Its design philosophy is anthropomimetic: rather than the rigid, high-precision links of industrial arms, Knight's robots use compliant structures with springs that behave like human tendons, an approach the studio summarizes as "a more human approach for a robot that can work next to people."^[4] Beyond the DexHand, The Robot Studio's portfolio includes ROSA, an anatomically detailed humanoid with more than 80 powered degrees of freedom that has been exhibited at the Science Museum in London; the Robot Nano Hand, a tendon-driven hand paired with an NVIDIA Jetson Nano for vision-based gesture control; and earlier research platforms such as the Hannover Torso and a high-speed android study.^[4]

The Robot Studio is also the origin of the widely copied SO-ARM100 (and its successor SO-ARM101), a low-cost 3D-printed robot arm designed in collaboration with Hugging Face and released under the permissive Apache 2.0 license for use with the LeRobot imitation learning framework.^[13] That arm, sold as a kit by several vendors for roughly $100 to $240, has made The Robot Studio one of the more influential names in the low-cost open-source robotics community and shares the DexHand's ethos of cheap, printable, hackable hardware.^[13]

The DexHand

The DexHand is designed as "a low-cost R&D platform for exploring grasping and manipulation for robots intending to use humanoid hands as their interface to the world."^[2] Its defining engineering choice is that the actuators live outside the fingers. Instead of packing a motor into each joint, the hand routes synthetic tendons back through the wrist to a bank of servos in the palm and forearm, which keeps the fingers themselves light and slim and close to human proportions.^[10]

In the canonical V1 build, 16 slim micro-servos drive the four fingers and the thumb, two standard micro-servos provide wrist flexion and extension, and an optional standard servo adds axial wrist rotation, giving the roughly 19 powered degrees of freedom cited on the project site.^[1][5] The bill of materials calls out inexpensive Emax micro-servos (models such as the ES3301, ES3302, ES3351, and ES3352, each a few dollars) for the digits, and Feetech serial-bus servos (SCS2332 for the wrist, SCS15 for rotation) where a wider controlled range is useful.^[1] Tendons are made from off-the-shelf fishing line: Sufix 832 braided line rated around 80 pounds for the finger tendons, with slightly thicker kiteline used for ligaments and wrist tendons.^[1] Knight has noted that modern braided lines show minimal drift over months of testing and that he uses a passive spring extensor so that only one side of each joint needs to be tuned.^[10]

Every structural part is 3D-printed, and the studio publishes print settings (for example a 0.6 mm nozzle with 0.4 mm layers for fast printing) alongside a parasolid CAD model that can be viewed and downloaded for free on Onshape.^[1][5] The all-in component cost is quoted at about $300 USD, which excludes the printer itself.^[1][2] All of it is released under the CC BY-NC-SA 4.0 license, permitting non-commercial sharing and adaptation with attribution.^[3]

Versions

Knight has described the DexHand as an evolving family rather than a single product.^[10] The public releases and roadmap he has discussed are summarized below.

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The NVIDIA question

A third-party open-source robotics directory (Growbotics) describes the DexHand V2.3 as a hand "from The Robot Studio and NVIDIA" and notes that support for NVIDIA Isaac Sim is "in the works."^[11] This framing should be read carefully. The primary project materials do not document a formal corporate partnership with NVIDIA; the phrase appears to describe planned simulator compatibility rather than a joint development agreement. In fact, Knight has been publicly critical of how existing tools handle hands, observing that no dedicated hand simulator really exists and that designers "try to shoe-horn it into Isaac Sim and it's still a pain."^[10] The clearest verified NVIDIA link anywhere in The Robot Studio's portfolio is hardware, not a partnership: the earlier Robot Nano Hand used an NVIDIA Jetson Nano as its onboard computer for vision-based control.^[4] Absent a first-party announcement, the DexHand is best understood as an independent open-source project that targets NVIDIA's widely used simulation and compute tools, not an NVIDIA product.

Community and ecosystem

The DexHand exists as a two-part community. The Robot Studio repositories (for example TheRobotStudio/V1.0-Dexhand) hold the original mechanical design, STL files, Onshape CAD, and bill of materials, and remain the best reference for the physical build.^[5] The electronics, firmware, and software layers were largely contributed from mid-2023 onward by Trent Shumay of IoT Design Shop, a maker who aggregates the whole project at the community hub dexhand.org.^[2][6]

IoT Design Shop maintains firmware for the V1 hand that runs on an Arduino Nano RP2040 Connect board and accepts commands over both Bluetooth Low Energy and USB serial.^[6][7] A companion example, dexhand-ble, streams joint angles to the hand and includes a demo that mirrors a human hand in real time using Google's MediaPipe hand-tracking library, plus preset gestures such as a wave and a "shaka."^[7] On top of that sits a set of ROS 2 packages (the dexhand_ros2_meta metapackage) providing a URDF description, RViz2 visualization, a gesture-based controller, and a USB serial interface, first released in October 2023.^[6][9][14] Notably, IoT Design Shop also published an LLM control package that lets a large language model such as ChatGPT drive the hand as an output device through the OpenAI API, an early demonstration of language-model-to-actuator control.^[6] IoT Design Shop additionally produced resin-print "remixes" of the hand geometry optimized for SLA printers, using tougher engineering resins.^[6]

Positioning among open-source hands

The DexHand is one of several open-source dexterous hands that emerged as reinforcement learning and robot manipulation research created demand for affordable, hackable hardware. Compared with its peers it sits at the low-cost, high-DOF, self-build end of the spectrum.

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The DexHand's tendon-in-forearm architecture most closely resembles the ORCA and Aero designs and contrasts with the LEAP Hand's direct-drive layout, where a motor sits at each joint. Its main distinguishing features are the extreme low parts cost, its close-to-human finger geometry, and the maturity of its community firmware and ROS 2 stack. Where ETH Zurich's ORCA hand ships with integrated tactile sensing, the stock DexHand does not, which reflects Knight's own view that integrated touch sensing is one of the field's key unsolved problems.^[10]

Limitations

The DexHand is explicitly an R&D and hobbyist-to-researcher platform, not a finished industrial product, and its constraints follow from that positioning.

• No built-in tactile or force sensing in the base design; the hand relies on precise position control rather than touch feedback.^[10][12]
• Hobby-grade servos and printed plastic parts limit payload, durability, and repeatability relative to metal-geared industrial hands; higher-rated versions (V4) are only planned.^[10]
• The non-commercial CC BY-NC-SA license permits research and personal use but restricts commercial deployment without separate arrangements.^[3]
• Documentation is split across two organizations and multiple repositories (The Robot Studio for mechanics, IoT Design Shop for electronics and software), which can complicate a first build.^[2][5]
• Simulation support is a work in progress, and the widely repeated "NVIDIA collaboration" label for V2.3 is not backed by a first-party partnership announcement.^[10][11]

See also

• Dexterous hand
• Humanoid robot hands
• Tendon-driven
• ORCA Hand
• TetherIA

References

1. The Robot Studio, "V1.0-Dexhand" (build files, BOM, and README). GitHub. https://github.com/TheRobotStudio/V1.0-Dexhand ↩
2. DexHand, "About." dexhand.org. https://www.dexhand.org/about/ ↩
3. DexHand, "License" (CC BY-NC-SA 4.0). dexhand.org. https://www.dexhand.org/license/ ↩
4. The Robot Studio, official site (mission, ROSA, Robot Nano Hand, company registration). https://www.therobotstudio.com/ ↩
5. DexHand, home page (project overview, ~19 DOF, ~$300). dexhand.org. https://www.dexhand.org/ ↩
6. IoT Design Shop, "DexHand: Open Source Dexterous Humanoid Hand" (Jan 8, 2024). https://iotdesignshop.com/2024/01/08/dexhand-open-source-dexterous-humanoid-hand/ ↩
7. IoT Design Shop, "dexhand-ble" (Arduino RP2040 BLE control, MediaPipe demo). GitHub. https://github.com/iotdesignshop/dexhand-ble ↩
8. IoT Design Shop, "dexhandv2_description" (URDF and ROS 2 description for DexHand V2). GitHub. https://github.com/iotdesignshop/dexhandv2_description ↩
9. IoT Design Shop, "dexhand_ros2_meta" (ROS 2 metapackage). GitHub. https://github.com/iotdesignshop/dexhand_ros2_meta ↩
10. Humanoid.guide, "Interview with Rob Knight: Building the World's Most Dexterous Robot Hands." https://humanoid.guide/interview-with-rob-knight-building-the-worlds-most-dexterous-robot-hands/ ↩
11. Growbotics Robotics, "DexHand v2.3" (open-source robotics directory listing). https://robotics.growbotics.ai/projects/hardware/dexhand-v2 ↩
12. Humanoid.guide, "Robot Studio DexHand V2.3" (product/spec listing). https://humanoid.guide/product/dexhand-v2-3/ ↩
13. The Robot Studio, "SO-ARM100 / SO-ARM101" (open-source arm with Hugging Face LeRobot). GitHub. https://github.com/TheRobotStudio/SO-ARM100 ↩
14. DexHand, "Initial Release of ROS 2 Support for DexHand" (Oct 1, 2023). dexhand.org. https://www.dexhand.org/software/firmware/ros2/update/2023/10/01/ros-2-package-release.html ↩
15. ORCA Hand, Soft Robotics Lab, ETH Zurich (ORCA vs. LEAP Hand comparison; arXiv 2504.04259). https://srl.ethz.ch/orcahand.html ↩
16. TetherIA, "Aero Hand Open" (open-source anthropomorphic hand). https://tetheria.github.io/aero-hand-open/ ↩