BSF toilet design workshop

Based on the winning ideas in our InnoCentive Challenge, we’re taking important steps closer to a sanitation system using Black Soldier Fly larvae.

Our recent online Challenge in partnership with InnoCentive proved the huge potential of open innovation. We’re immensely grateful to InnoCentive for their generous support in giving us the Challenge.

We asked InnoCentive’s worldwide Solver community to develop an affordable and user-friendly system that will allow Black Soldier Fly (BSF) larvae to be used to reduce waste mass in pit latrines. The larvae can then be harvested and used elsewhere as an economic resource.

The Challenge inspired a fantastic response, leaving us in a strong position to move towards prototyping a system. After selecting four winners from almost 50 entries, we brought together members of our diverse network for a two-day workshop in London, to decide the next steps. Our team was joined by the overall Challenge winners and representatives from Oxfam, AgriProtein and the Bill & Melinda Gates Foundation. Six design students from the University of Middlesex worked alongside us bringing fresh perspectives and design thinking.

From Challenge to Prototype

Black Soldier Fly WorkshopAfter brainstorming, model-making and mulling over the tricky issues of designing a system that can be retrofitted into existing latrines, we selected two ideas to develop for prototyping. Both harness the natural movement of pre-pupal larvae away from food, towards dry dark crevices – perfect locations from which to harvest them.

One of these was also the overall InnoCentive Challenge winner – ‘the Kone’, designed by Emil and Erik Martinsson, water and waste engineering consultants from Sweden. Their flexible rubber cone can be pushed through a small latrine hole to be suspended inside the pit on the sludge surface. When they reach the prepupal phase, larvae migrate up its sloped sides into a removable collection pot. The cone is then pulled up every few weeks so the pot can be removed, emptied of larvae and replaced.

The other idea we’ll develop and prototype – the ‘Daisy Chain’ – is a flexible, lightweight circular tube which floats on the sludge surface. Larvae migrate inside through multiple access points. The tube is pulled up using a hook, and larvae emptied via the squat hole, again without removing the whole system.

Although the Challenge was about designing a system that could be fitted into existing latrines, the workshop generated interesting ideas for a contained system integrated into a specially designed latrine or toilet. Expect to hear more about this soon.

The workshop also highlighted additional directions for our research into BSF behaviour. For example, how far can the larvae travel, and how fast? Which materials deter or promote their movement?  What can they climb into but not out of? Can we create a chemical lure to increase the chances of them migrating to where we’d like them to? We’ll feed this knowledge into the development of our prototypes and new designs.

Building the Business Case

Building the business caseWe’ll continue working with Emil and Erik to take both our lead ideas to workable prototypes. They’ll examine the key design questions raised in the workshop around each approach and – critically – also consider how to make servicing the Kone and Daisy Chain safe and acceptable for users and for whoever installs, empties and maintains the system. This is vital, both for consumers’ health and dignity, and so that we can create a product that’s commercially viable. People must want to buy and use it, so it can support business ventures that are sustainable in the long term. This way, we’ll have the most impact on people’s lives in developing countries.

Sign up to receive updates during 2012, as we develop and trial our prototypes, before selecting the most viable approach for business case development.

Congratulations to the other winning Solvers of our InnoCentive BSF Larvae Challenge:

Kevan Stokes of Augmentias, Raz Lupa at, and Winston Ford of Urban Feed Co

Many thanks for your innovative thinking and great designs.

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