Project description


Rezero is the name of a unique Ballbot, able to balance and drive on a single sphere. Especially designed for high acceleration, it moves in a very organic and elegant way. Rezero is the first Ballbot prototype which is able to show the full capacities of a Ballbot.

  • Video Performance and Interaction
  • Video Technic Rollout
  • Video Design

The development of Rezero was inspired by other Ballbot projects like CMU Ballbot and BallIP.


A Ballbot moves on a single ball, not on wheels. This is both astonishing and creates a new means of mobility for robots. A Ballbot can move spontaneously in any direction and does so in a manner as smooth and elegant as a figure skater on ice. Whether used as a guide, a toy, a service robot or a daily aid, a Ballbot can prove its potential in a narrow, varying and crowded environment.


Rezero is the first Ballbot which does not only focus on stability, the calm balancing, but also aims at high agility, the fast movement. Primarily, Rezero is meant to entertain and impress. It is supposed to create emotions. It will be able to interact with a small group of people, react on attractions and in doing so create a hands-on experience with the Ballbot technology. The Ballbot will be an ambassador of its own movement skills. Its dynamic hull even allows Rezero to show and create emotions. Imagine Rezero breathing, being curious or frightened. And even waking up or going to sleep by revealing or retracting its sphere.

Rezero bridge Rezero slalom Casing concept


Along with the choice of technically high-class and performance optimized parts, we concentrate mainly on the drive and the power transmission on the ball. Here, we also want to create as much propulsion as possible with as little weight as possible. Three driven omni-wheels, wheels which rotate freely in the direction of the axial, allow us to completely control the sphere with almost no undesired friction. High-tech sensors and a robust system control form the heart of Rezero’s electronic system. Completed by distance and sonic sensors in combination with many other components it forms the experience of Rezero.


Rezero presents itself in elegant white and lively blue. The design communicates the ballbot’s agility and gives Rezero abstract character. The casing is able to vary in height in order to bend its fins and give insight in the illuminated core of Rezero. This, interpreted as breathing, heartbeat or posture, provides Rezero an innovative way to express itself. Synchronized with its movements, this dynamic appearance astonishingly underlines Rezero’s unique potential in motion. To park Rezero, its casing can be lowered over the ball, thus it is able even to stand stable.

Skizzen Formskizze Dynamische Verschalung Modell Foto


An optimistic view in the future exposes inspiring perspectives for Ballbots. Equipped with an interchangeable hull, Rezero would be probably the most agile advertising message ever. And a few modular upgrades could turn such a Robot into a Photobot or Runbot and provide the fundament for broad and meaningful usage. Boundaries are set just by your imagination.

Sponsor Bots Photobot Screenbot Beambot
Runbot Medibot Secubot Freshbot

Focus Project

Within their Bachelor courses, Mechanical Engineering students at ETH are able to focus on a project work. In a team ideas are developed and fixed, with the goal to create a new product or prototype within one year. The approach to their own problem is freely chosen by the team members, supported by academic and industrial experts. Starting with an idea, the students are responsible for all necessary steps for the prototype, including

concepts, calculations, design, manufacturing and assembly. However, also soft-skills, not only within the team, have to be taken into account. Suppliers and Manufacturers have to be convinced and in discussions with experts information and knowledge needs to be gained and finally integrated into the project.

Further Focus Projects this year are Hyraii, Alcedo, AMZ and Hermes.

TED Talk

TED Talk - Péter Fankhauser: Meet Rezero, the dancing ballbot