This past weekend, the team here at Tiny Farms had the opportunity and honor to participate in the first ever Food Hackathon here in San Francisco. Not only did we have a ton of fun, we also took the prize for Best Hardware Hack and got to feed waxworm baklava (‘buglava’) to a bunch of curious bystanders and the whole panel of judges.
Well over a hundred of us enthusiastic participants showed up – hackers, designers, and visionaries all of whom love food. The organizers put on an amazing event with two days of intense focus hacking the food system, fueled by outstanding coffee, food and beer. For a great write-up of the event check out this article from Xconomy (http://www.xconomy.com/san-francisco/2013/04/08/food-hackers-cook-up-a-storm-of-startup-ideas-in-san-francisco/)
Basically the weekend was awesome! And we had the opportunity to build a solution to one of the real problems we face in our insect rearing efforts. Specifically, we tackled how to separate mealworms from the wheat bran they live in. For those who have never attempted this particular task before, it’s a pain. The flakes of bran that the worms love to live in are similar in diameter to the worms themselves, so they cannot be easily sifted out through a screen. However mass and aerodynamics of the flakes and the worms are vastly different which provides a variety of other options. After considering a range of options including vibrating platforms, static electricity and water, we settled on using airflow and some good old gravity to separate the bug-meal-mix by shape and mass. With the help of our two volunteer teammates we ran, built and tested a pile of prototypes with several iterations on each. In the end we were left with three parallel approaches that all worked! Here’s an overview:
Video of trial runs using various prototypes – at the end, we used rice to imitate bigger worms (our actual worms were little babies!):
The Bug Cannon -
We fed the bug mixture into and inclined tube with airflow coming up from the bottom. Based on a bunch of testing we found a good combination of air pressure and incline angle that resulted in a clean separation between the worms and the meal. Once we found that point, we set up the “hopper” to feed the mix into the tube just above this point so the bran was immediately blown up the tube and the bugs slid down and out a chute in the bottom. Our final prototype was not very pretty, but it worked pretty robustly handling a relatively high volume of inflowing bug mix. It was also remarkably cheap to build. Many of the materials were actually scavenged from the event itself, and the only moving part was a cheap air-mattress pump we found in the trunk of our car.
The Nautilus -
This approach developed by Jena and our new friend Mariel is similar in concept to a Dyson vacuum, this approach utilized a macaroni shaped chamber with air flowing in the bottom to create a vortex of air that kept the heavier worms circling in the base while the lighter bran flew out the top. The original prototype for this was made with strips cut from aluminum cans, and an improved version was made with moldable plastic. We did not have time to fully develop the feed-in to supply bug-mix to the chamber, but the separation was remarkably effective and the model is extremely promising.
The Drop -
Our final design, single-handedly designed and constructed in record time by our other new friend Matt, is based on the principle of dropping a thin stream of bug mix through a stream of air. The mixture is spread by mass and volume as it hits the stream of air and the separated bugs can be collected as they continue to fall, now free of bran. Initially we thought we could simply drop the mix past some airflow and the components would land below neatly divided. Sadly this did not work out quite so easily. Although the worms fell in a fairly tight group, the bran spread back out once it cleared the stream of air and mixed back in with the bugs. To solve this, Matt set up multiple fans and positioned shelves to collect the bran just below the points of mid-air separation. With just a few spent tweaking the arrangement, he managed to cleanly remove the bran from the falling worms and provide them an exit route.
With these solutions in hand, we are now equipped to harvest mealworms quickly and easily. We also met a ton of awesome folks working in the food space and were extremely happy to find everyone was very receptive to the idea of utilizing edible insects as a sustainable food source.
After this huge success we can’t wait for the next Food Hackathon (which is already being planned for later this year and the chance to meet more amazing people and solve more problems.