I found very interesting youtube videos from Carl Bugeja (i.e. video) who used a multi PCB coil to actuate a spring suspended magnet. I thought this could be a very nice way to actuate my valve directly electrically without using pressure. Glueing the magent to the silicone and using the PC as top plate could form the electrical actuator for the valve.
My second attemp was to move to micro valves. I will need normal off valves since the final apperture should be stable also when not supplying a voltage. I milled again channels (three at the same time, middle block) and put a silicon sheet in between (left). The top acrylic I had 3 inlets and 3 outlets. In the middle three inlets to control the valves.
The top plate I countersinked the control port of the valve a bit that the silicon could be sucked in.
As basic setup I used an Arduino Nano controlling a mini pressure pump (in vacuum mode) and a pneumatic valve (not shown in picture) and try to pump some water. The setup shown was one of some different tires I had.
Results; In general it worked .... a bit. The main problem were:
depending on how tight I screwed the screws the valve was not tight enough and the varuum sucked the water all the time or the valve was to difficult to open, that I even could not operate it with mouth sucktion.
In the beginning I used 3D printed hose connecters (i.e. the blue one at the water reservoir) but they had not been as tight as well as they broke when I had to remove the hose.
I tried 6 different valve design / dimensions and countersinks. I also ordered different silicon material as well as one set of liquid silicone.
The athmosperic pressure sensor range was way to small (or my pump to strong :-)). I tried to order another one without going in the costly range.
I think I need some more inspiration how to make it work. It should be possible this way, but I did not really understood the effect chains and how the design parameter influence the behavior exactly.
My first tries have been two acrylic (=plexiglass) 6mm thick pieces where I milled in two tesla valves and a slot for a piezo buzzer. Screwed both parts together and glued the piezo in. Connected two 3mm (inner diameter) tubes and driving the peizo with an 12V PWM in frequencies up to 60kHz.
It pumped a bit bit overall it was not very successfull, so I continued my research. I also ordered some piezo's with divers used to generate mist which I might try at a later point ofg time.
The idea to have my own salt water aquarium grow up the last years. However, I am a bit hestitating because of the effert you have to do to keep it running. One of the main components missing to set up a fully automatic aquarium is a full automated tester and so I started research how to realize such a DIY product.
The professional device Reefbot V2 basdically does the job with in a bulky and mechanical way, and for quite some costs. The REEFMASTER startup seams to go an improved way with fluidic valves but still not on microfluidic level.