Need help finding a small, cheap, Arduino-ready solenoid valve or pump assembly
December 12, 2012 11:10 PM Subscribe
I need some help building a gadget with an Arduino board. Specifically, I need help finding a way to dispense very tiny quantities of fluid (10 μL) once an hour. The valve assembly is the part I'm having trouble with...
posted by dialetheia to Technology (14 answers total) 1 user marked this as a favorite
I am trying to build a hummingbird feeder that dispenses ~10 μL (+/- 5 μL) of "nectar" (sugar-water) once an hour. I feel like I can figure out the Arduino/motherboard part of the assembly, but I'm having trouble finding the right valve or pump setup. It seems like somebody would have solved this problem to dispense tiny, precise quantities of ink, but I'm having trouble finding similar projects.
I intend to put the nectar in an IV bag (to keep it from being contaminated over 2 weeks in the tropics), which will be inside of a waterproof container along with the electronic components. The nectar will dispense into a feeding nozzle via some sort of electronically-controlled valve or pump.
The feeder should be able to run for at least one, preferably two weeks without maintenance, including changing batteries (hoping and assuming that battery power will be sufficient for this).
The cost of the project needs to be less than $50, and maybe ~$7 of that is already allocated for the non-electronic parts of the feeder.
I've looked at using a solenoid valve, but most of the affordable ones seem to be too big and have really high flow rates for the tiny volume of nectar that I need to dispense. Going with the solenoid valve option also means that I have to find some way to provide pressure inside the container, since all of the small valves I can find require at least 3 PSI of pressure to work.
The volume of liquid I need to dispense is so tiny that the drops won't have enough mass to break the surface tension of the water, so gravity-fed valves probably won't work(I think). I was considering using a tiny pump to regulate the flow, but I haven't had very much luck finding anything small enough that is also affordable (and I might still need to combine this with a solenoid valve anyway, I haven't thought it quite all the way through yet).
Does anyone have any ideas for how I could regulate the nectar flow through my feeder using a simple, entry-level Arduino DIY setup? Good cheap tiny valves? A better way to approach the problem? Cheers for any guidance you can offer.