There are several ways to freeze the fall and splash of a fluid drop. Trial-and-error is one of course, but the yield is very low and you need to be very patient. Being a non-patient engineer, I felt this had to be done in a different way :)
Stimulated by capturing crushing of glass and light-bulbs, I made a slightly different setup to control the release of a flash in darkness, when a drop of fluid started to fall.
- A drop forming device was formed of a twisted nail with a large head.
- A low-cost 2mW laser (a laser pointer device is okay as well) is aligned to have its beam crossing non-perpendicular of the drop formed.
- A photo-transistor is aligned to have its focus in the extension of the beam
- When a drop is formed, the beam is deflected and the detector gets less light
- When the drop is released, the beam hits the detector gets full light
