DIY Electrostatic Dust Print Lifter

Hello everybody, hope you're doing well

in this instructable I'm gonna show you how to make an electrostatic dust print lifter. At this point, you are probably wondering what is an electrostatic dust print lifter? Electrostatic dust print lifter is a device that is used to pick up prints (footprints), it works by applying a high voltage electrostatic charge onto a piece of lifting film (usually Mylar) which is placed over the footprint. A device that works on a similar principle is used by forensics to recover dust prints in the field.

This project requires working with high voltage, so if you plan on making something like this be careful with all the tools, do not mess with electricity, be careful, and if you decide to give this project a go yourself, you are doing that at your own risk.

Some kind of box

High voltage generator

Switches (one toggle switch, one push-button switch)

Li-ion battery with protection board

Female charging port/connector

Banana connectors

Wire connectors

Paper clip

Car window tint (sunlight blocking film)

Alligator clip

Multimeter probes

Piece of metal (I used a scrap piece of aluminum)

Two small metal rods

Flashlight

Tools: Soldering iron as well as some solder, wire cutters, needle-nose pliers, utility knife, insulated terminal crimping tool/pliers, hot glue gun.

In the photo above you can see the main components required for this project.

I decided to write a few words about these components because these are the main components required for this to work.

A high voltage generator works by converting a DC (from a battery) into pulsating DC which goes into a transformer (step-up transformer) and from a transformer into a voltage multiplier circuit. And voltage multiplier circuit consists of a ladder network of capacitors and diodes. In this project, car window tint is used as an alternative to mylar because it is not hard to find and it works great. I tried a few different materials but the car window tint had the best performance.

I found this box which opens kind of like a drawer (out of the front), and it had some kind of lab equipment look to it which is great because this device is a piece of lab equipment :), anyway I first place components in the box and I planned out the situation before connecting components accordingly.

First I measured the dimensions of the switches that I used and I traced those dimensions onto the box. Because my box opens like a drawer I had to position those switches near the front (front part of the box) and to make holes for the switch I used a soldering iron (hot knife method) to cut the holes and I used a utility knife to remove rough edges.

I also used my soldering iron to make 3 more holes for banana jack female connectors, and while those are commonly used on lab equipment, they gave this build a surprisingly professional look, so the ending product looks like a piece of lab equipment. Now you're maybe wondering why I made 3 holes? The reason for that is because I used two of those for ground connection (black banana jack connectors), those two are connected together so they are on the same potential.

Once again I used a soldering iron method to make one more hole, this hole is for a female power supply/charging jack. I also used a saw on my Swiss Army Knife to remove any rough edges, by the way, this is a useful SAK life hack, especially because most people would probably use the blade instead of a saw.

In this step connect the battery with a li-ion protection board, on the li-ion protection board there are 4 connection points BAT - and BAT + are for battery and IN - and IN + are for charging (this is where the female power supply/charging jack connects to)

In this step install female banana jack connectors ( 2 black, 1 red), and also install a female power supply/charging jack.

In this step make a spark gap, and spark gap is important here because without it high voltage module would probably be ruined very quickly. Making it is fairly simple, start by straightening out a small portion of a paper clip, then cut out two pieces, and then bend them into shape. This is pretty easy with a pair of needle-nose pliers. And last step here would be to screw those into a wire connector. Make the spark gap about 4 mm wide.

To start this step prepare 2 wires, these two wires go from spark gap to the female banana jack connectors, and these ring insulated terminal wire connectors are used to make reliable contact with the female banana jack connectors. Note that for this task it would be better to use insulated terminal crimping tool/pliers than for example needle-nose pliers.

I also soldered those two wires to the wire crimp connectors, and two other ends go to the output of the high voltage generator.

Wiring it up is pretty simple, but make sure to connect the battery into the circuit after you connect other components accordingly (this is one more safety measure).

As I mentioned before wiring it up is pretty simple and this is how it goes: output of a high voltage generator connects to spark gap and banana jack (with those two wires from the previous step). One wire from the battery goes to the input of the high voltage generator, and the other one goes through the switches to the other input wire of the voltage generator, and that is it. The last part of this step is to close the box, I used 4 screws.

I had an old pair of multimeter probes, and I used those here, but I slightly modified them, first I cut off the ends on both of those probes with a utility knife so that they would be compatible with banana jack connectors, at this point the red one is finished while the black one still needs to be slightly modified. I cut off the other end from the black probe and I replaced it with an alligator clip, which I also soldered, after that, I covered that joint with a bit of hot glue and heat shrink tube, and then after that, I put some gaff tape on it as well.

At this point, the main unit is completed! One more thing that is left is to prepare car window tint films.

To prepare lifting films cut out the sheets (from a car window tint) using a pair of scissors.

To set up this device start by placing a piece of metal on the ground near the print, then position the film on the print, if needed use two small metal rods to keep the film in place after that connect the black probe to the metal piece and that is it.

Now for this to work there has to be some kind of charge difference between lifting film and surface that has a print on it, so the circuit needs to be closed somewhere. This device works by applying a high voltage electrostatic charge onto a piece of lifting film (car window tint) which is placed over the print that needs to be lifted. A piece of metal (in my case aluminum) provides a connection with the ground. Because of that charge difference between lifting film and the surface on which it rests dust particles are attracted and then attached to the film, bearing the print.