Quantity   Component name
7 × V165V01 12V Normally closed miniature direct solenoid valve, DC 12 V, 2x M5 interface
1 × Car windshield water pump 12 V, about 1.5 bar pressure
1 × 4x optical isolator board
1 × Arduino nano
1 × 12 V 7 Ah Lead acid battery Or other battery to supply 12 V, capable of delivering at least 7 A. Exact current based on water pump and valve types used. Count that everything will be powered at once!
1 × Wires, mechanical switch Not exactly specified
1 × Pneumatic hoses 8 mm, 6 mm, pneumatic connectors As needed
7 × Nozzle We have used 3d-printed nozzle. A nozzle for pipetting could work as well.