@lizbarry Talked today about color change methods. There’s more and more in the ag space, around both water quality, soil quality, and other stuff. Here’s a few things I’m aware of / things we’re working actively on:
heard from a friend in the ag space (especially regenerative ag) they are quite excited about this --> https://microbiometer.com/purchase?olsPage=products%2Fsamplesoilhealthtest . This is a soil test that differentiates, in the field, the types of microbiology present. They use a card-based color change method, and their app has software for quantifying the color change from an image. The typical method for this (which I think they use) is to normalize the camera to a black/white or colored object on the card which is standard.
We’re going to try to run a few environmental tests, like these enzyme based tests for nitrates, total nitrogen, and phosphorous - https://www.nitrate.com/ , on the dropbot (https://sci-bots.com/). The color change can be quite subtle, so the tests we’ll run will be mostly to determine the accuracy we can get from the test - here’s more from Ryan - [hackathon project] Developing an automated workflow for colorimetric testing using digital microfluidics. We will likely try to differentiate color using a specially designed spectrometer from Alex at U of T, the Our Sci spec, and just images via openflexure to see what works and how well. The key here is once we have a repeatable method of known accuracy to color changes, we can then broaden that really to any color change method that can be done using the dropbot (meaning you need to move, mix, or wait with the liquid). There’s a lot of those! Also, other than using the dropbot, we can already do this all on the colorimeter / reflectometer we built, but of course that’s in larger quantities one shot at a time (and we sell it through BFA as a developer kit, but it’s just a colorimeter - http://bionutrient.org/site/bionutrient-meter.