Develop an indicator for Solar Water Disinfection

Dear supporters,

2012 has been a busy year with some significant progress on the SODIS indicator. You probably are aware that the objective of this project is to develop an indicator which can tell a user when water in PET bottles has been exposed to enough sunshine and thus is ready for consumption (for more information on this fascinating process, please visit www.fundacionsodis.org). The main challenge is to do this at a very low cost, because this device needs to go to millions of people around the world, most of whom live on less than a dollar per day.

So far, we have managed to develop several prototypes, all of which do the job fairly well. However, as long as we are working with prototypes, a lot of manual work is involved, which makes the units expensive. Thus, we need to produce on a different scale (mass production), but also to make sure that we got the design right. "Getting it right" in our case means three things:

1) The indicators need to work properly, indicating the users when they have to wait and when the water is ready for consumption.

2) The devices have to withstand very rough conditions (heat, sunshine, wind, rain, etc.).

3) They need to communicate in a very simple way with the end user when the water is ready for consumption.

In order to achieve this, we are now preparing a field test with some fairly advanced prototypes. At the moment, they are still too expensive, but before we start mass production, we need to make sure the design we are working with is the right one.

The devices we are working with are made of a radiation sensor, an electronic circuit and some kind of a display (typically LEDs). In parallel, we also work with an alternative approach: Paper stickers which change color depending on the amount of radiation received. In cooperation with the University of Cochabamba (Bolivia), we just completed a series of tests with one of these products, which shows promising results: The paper changes within 8 hours from red to yellow (see picture above). However, the product is not re-useable and the color change is slightly too slow for our purpose. Therefore, we are now looking for alternative products and for mechanisms to make the indicator re-useable.

We will keep you updated about progress on our side. If you found this report useful, feel free to share it with your friends and family and pass on the word.

With best regards from the whole project team,

Matthias Saladin

Links:

• Website of the SODIS Foundation
• Visit us on facebook

Dear supporters,

Every 20 seconds, a child dies because of diarrhea. As diarrhea is mostly caused by poor water, sanitation and hygiene conditions, we feel that our project can make a difference in this regard. In the project, which you supported in the past, we want to develop and produce a low-cost device to tell the user when their water is safe for consumption by making use of the method of Solar Water Disinfection (SODIS). Here is a short update from the latest developments:

One of our partner organizations (helioz.org) has just managed to produce a first small series of their indicator. We are currently talking to this organization on how to obtain funding for a field test - we want to give this device to 1,500 families in order to collect more data on the use and usefulness of the current design. Producing the device was just a part of the project, we now need to obtain funding for the distribution logistics, for the field promoters and for the data collection process.

This field test is important as it will help us identifying what are the key factors for an adequate product design. In our case, indicating the user what to do is not as simple as you'd expect: We need to distinguish three different states (turned off; turned on an in progress; ready) and communicate these states to the user in a simple way. As we want to use the indicator with low-income families and with people who often are illiterate, we need to find ways of communicating with the user without the use of text. In order to be able to use the same device in a number of different cultural settings (not only in Bolivia, but in Latin America, Africa and Asia), the communication also needs to be universally understood. Luckily, the spread of mobile phones in many low-income countries helped to establish a set of almost universally understood icons and we expect to use some of them (e.g., a smiley).

Meanwhile, we also want to test alternative designs. Ideally, we’d be able to field test different products simultaneously in one setting in order to compare their effectiveness and reliability. We hope that by creating some competition among different providers we will obtain the best results: a low-cost indicator which can help thousands of families to determine when their water is safe for consumption. With a small donation, you can support us in this task and be part of a simple solution for saving lives.

Thanking you in advance and with best regards from the project team,

Matthias Saladin

Links:

• Website of the SODIS Foundation