Nano-WATA for disinfection and water treatment –
Call to the community for 3D printing of parts


For 15 years, the Antenna Foundation has been developing the WATA solution for disinfection and water treatment, facilitating access to it for as many people as possible.

WATA is a simple and robust solution certified by the WHO in 2019 (WHO Scheme to Evaluate Household Water Treatment Technologies). The technology is based on a simple electrolysis process that transforms a saltwater solution into a sodium hypochlorite solution (active chlorine).

> More information on WATA technology

In order to make this technology accessible to the greatest number of people and in the most remote areas, the Antenna Foundation now presents Nano-WATA, a small electrolyser allowing the production of 80mL of sodium hypochlorite [6g/L] in 20 minutes. This quantity is sufficient to produce:

  • 0,6L of disinfectant solution for surfaces
  • 1L of hand sanitizer solution
  • And treat up to 320L of water

The Nano-WATA device has the following features:

  • Simple, robust and compact: only salt and water are needed
  • Automated production: a light flashes when the production is finished
  • The device does not require any particular maintenance, measures 12 cm and weighs 60g.
  • Low power consumption and USB power supply

Call to the 3D community

Antenna Foundation would like to warmly thank the 3D community for its contribution to the production of the first 100 Nano-WATA devices! They are now being used for research, for local confirmation of their results, as well as by final users, among others in the DRC, in Brasil, Ghana, Nepal and Cameroon.

We now again need to produce a series of devices, to make the Nano-WATA technology and disinfection accessible to our current and future partners in the field.

Once all the parts are available, we will assemble the devices at our office in Geneva and distribute them in the field.

The Nano-WATA device is composed of:

  • 2 electrodes for electrolysis
  • An electronic board to control the production
  • A USB power supply
  • A 100mL bottle
  • A 3D-printed screwed support to hold the electrodes and the electronics in place

We are reiterating our call on the 3D community, to provide us with individual parts, to assemble and distribute as many of them as possible in the coming weeks. We are aiming at 150 parts as soon as possible

If you are interested in the project, and you are able to print one or more parts in 3D and send them to us, you can download the stl file and send us the parts to the following address.


Antenna Foundation
Nano-WATA Project
24 Avenue de la Grenade
1207 Geneva, Switzerland


  • Download the file 
  • Materials: PETG (In order to resist temperature and humidity changes and the chlorine solution produced).
  • Colour: Whatever you have in stock.
  • Quantity: Any contribution of 1, 10 or more pieces is welcome.
  • Printing direction: According to our tests, it is better to print with the screw side down.
  • Layer height: 200um
  • Perimeter: 3 or more
  • Filling: 20% or more
  • For more information about printing, you can write to


If you have contacts with potential partners or you work for an organisation where the device could be useful with your field activities:

Send an email to  Antoine Schelling and specify

  • Name of the organisation
  • Contact details of the local person who would report to the Antenna Foundation on the use of the device
  • Intended use of Nano-WATA

> More information about Nano-WATA