EPFL CHILI Lab Cellulo

EPFL CHILI Lab (Switzerland) Cellulo (1)

EPFL CHILI Lab (Switzerland) Cellulo (2)

EPFL CHILI Lab (Switzerland) Cellulo (3)

Not for saleNever sold, and no spin-off company was found. EPFL's Learn center describes it as a research initiative (October 2026 check). IEEE Spectrum reported the research versions cost about $135 each, and the HRI 2017 paper's parts table totals about 126 per robot at the prototype stage (currency unconfirmed). Year 2017 is the HRI paper, which won best paper. The project began in 2013, and a redesigned version 2 (Cellulo Modulo) followed in 2021.

Not for sale (research)Python from a laptopPalm-sizedMoves on printed paperUp to 7 per tabletHaptic feedback

Not for saleShipping: Not for sale. Never sold. Mechanics, electronics and firmware for both versions are on GitHub (no license file was found in the hardware repositories), so a lab would have to build its own.

Remote control: Activity apps are developed and tested on Mac, Windows or Linux with Qt/QML (or Unity), talk to each robot directly over Bluetooth, and are then deployed to iOS or Android tablets. ROS nodes also expose each robot's pose, touch keys and velocity.

GitHub (Cellulo) ↗Version 1 hardware and firmware ↗Version 2 ↗EPFL Learn ↗HRI 2017 paper ↗IEEE Spectrum ↗

Overview

A palm-sized haptic robot from EPFL's CHILI lab meant to be a classroom tool rather than something to program, used in studies on primary-school lessons, handwriting training, stroke rehabilitation and games for older adults. It rolls on ball wheels over ordinary printed paper and reads a microdot pattern underneath to know exactly where it is, so it can move on its own, push back against a hand, or be dragged around freely. Several robots work together through a central tablet or computer, not by talking to each other. Each robot keeps its own Bluetooth link to the tablet, which runs the activity logic and formation control and sends commands, and the paper reports up to 7 robots per tablet due to Bluetooth limits, with larger activities using several tablets in the same room. The catch is that it was never sold, many version 1 parts are discontinued, and version 2 is described on GitHub as having only one stable prototype.

Specifications

Category	Wheeled rovers · Research mobile manipulators & platforms
Released	2017
Country	Switzerland
Availability	Not for sale (research)
Programmability	Full SDK
Built-in autonomy	None / scripted · Moves only when controlled, or plays preset motions
LLM support	Possible via SDK · No LLM features. Activities are apps on a tablet or computer (QML/JavaScript, Unity or ROS), which could in principle connect to an LLM through custom code.
MuJoCo simulation	None found · Nothing found.
NVIDIA Isaac simulation	None found · Nothing found.
Gazebo simulation	None found · Nothing found. EPFL's ROS swarm-robotics course package for Cellulo emulates proximity sensors between real robots, but no Gazebo, ARGoS or Webots model was found.
Best for	Professionals & labs
Vision sensors	No vision sensors
Actuators	Unknown
Audio	No audio
Compute type	Arduino / ESP32 / microcontroller
Remote control	Python from a laptop
Size	About 75 mm across, hexagonal (second revision)
Drive	Three permanent-magnet-assisted ball wheels, holonomic, so it can move in any direction and be pushed by hand without damage. Version 2 also tested omniwheels
Compute	PIC32MZ1024ECG064 microcontroller (version 2 adds an ESP32 for communication and peripherals)
Vision	Downward-facing camera that reads a microdot pattern printed on the activity sheet, giving its own position about 93 times a second to about 0.27 mm and 1.5°
Lidar	None
Sensors	Downward localization camera, 6 capacitive touch buttons each lit by RGB LEDs, detection of being lifted off the paper, Bluetooth 2.1 (RN42 module)
Runtime	Not published
Speed	Not published
SDK	Bare-metal C firmware, Qt/QML plugin (cellulo-qml-plugin) for tablet and desktop apps, Unity SDK (GPL-3.0), ROS packages from an EPFL swarm-robotics course, tools to overlay the microdot pattern on any PDF and mark active zones