Develop an indicator for Solar Water Disinfection

The quest for the development of a low-cost indicator for solar radiation continues. In this report, we would like to comment on some exciting developments we observed in the last few weeks:

- One organization we mentioned several times already, Helioz GmbH of Austria, are in the process of producing a first series of their electronic SODIS indicator. The SODIS Foundation is one of the organizations who will be able to try the indicator under real-life conditions.

- A group of investigators and designers from Italy are working on a novel approach for the SODIS indicator. The idea is to have a material which changes color after being exposed to sunlight, and which can be used several times. This would significantly lower costs of producing such indicators and transporting them to remote areas.

As you can see, several groups and institutions around the world are working on the same objective, independently from our work but often in a collaborative manner. We will stay in contact with these groups and discuss ways on how to implement the different approaches in the field. A key question we need to address is how the indicators are used: either by the users directly (which means we need a lot of indicators, but probably will create more trust and a richer experience for users) or by trainers of end users, who will use there devices as a teaching tool for the surrounding families (which means we need fewer devices, but people will not be able to obtain first-hand experience).

We will keep you informed about these and other developments in the coming weeks.

Best regards from the whole team,

Matthias Saladin

PS: In order to avoid misunderstandings, we would like to make it clear that the activities of the groups mentioned in this report were not financially supported by the SODIS Foundation. The donations received for this project through Global Giving so far have been used for field testing in Bolivia and for coordination activities of the SODIS Foundation.

Dear supporters,

We wanted to let you know about the exciting latest developments at our project. As you may know, we want to develop a device which tells users of the SODIS method (Solar Water Disinfection) when a bottle has been exposed to sufficient amounts of sunshine and the water is safe for drinking. We have been working with several companies and research groups around the world, and so far we have focused on electronic devices. However, we are now also using a second approach, which is based on colour-changing materials. These can be delivered in the form of stickers to the users, taking up very little space and for a fraction of the cost of an electronic device.

In May and June, we have been in contact with a group of scientist at Queens University in Belfast (Northern Ireland), and they have advanced significantly in the develpment of a prototype. Basically, they exposed different colour-changing materials to strong sunlight and measured how quickly colour changes. The results look like a bunch of coloured dots, but based on these results they can develop an advanced prototype, which we then will test in the field. Ideally, we want to have a material which is re-usable for many times, but this is a major technological challenge (the materials need to "recover" overnithg). Thus, for the moment we will work with disposable materials, but also keep derveloping the re-usable ones - they will be more cost-effective, save limited resources and produce less waste.

Please let us know if this report has been interesting and useful for you. If so, please share this message with someone who might be interested in this project and in supporting our cause of improving drinking water quality of marginalized people in Latin America. Obviously, we are still several months away from a finished product which may benefit millions of people. In the meantime, if you want to support a project with immediate impact on improving drinking water quality, have a look at our micro-project for 18 day care centers in Cochabamba (see link below).

Best regards from the whole project team,

Matthias Saladin

PS: Just to avoid misinterpretations, we would like to clarify the the work of Queens University is directly funded by institutional donors, not by the SODIS Foundation. Our support focused on establishing links between different research groups and to identify an ideal place for field testing. The funds we receive through Global Giving are used for our own tests and for coordination activities.

Links:

• Project to provide safe drinking water for 18 daycare centers