A vacuum pen is used to pick up tiny little things such as beads, small shells or sometimes electronic components depending on their size. They aren't very useful for picking up larger things like coins or larger computer chips, but are great for things so tiny they are hard to even pick up with your fingers, especially if it's something you are worried about crushing. They sell manual press pumps for around $10 that can do this but if you want a little more oomph in your suction ability, an electric vacuum pen can be the the way to go. Unfortunately those can be much more expensive starting at $50 to $80.
My goal while making this was to do it for as little money as possible, so I will try to lead you on how to do that too. This one was under $20 in total parts, and half of it was stuff I already happened to have around the house.
Step 1: Parts And Tools.
This vacuum pen was made with some easy to find parts. The main component is the aquarium air pump. This walkthrough is specifically for the Aqua Culture duel pump for 20-60 gallon tanks and the Whisper 100 which we will cover after (jump to page 16 if you want to start on the Whisper 100.), which is rated for 100 gallons and has a little more power, but also cost a little more. It will depend what you want to do. Walmart has the best price for the Aqua Culture I've seen for around $10, but if that's not your thing, ebay is probably the next best place to work for price. The Whisper 100 seems to go for just a little over $20.
Keep in mind before you start, the more gallons the pump is rated for, the more suction it would have. This is a $11 pump rated for 60 gallons at most. The Whisper goes up to 100 gallons and would give you slightly more suction, but that pump is around $20. They also make pumps for ponds and larger tanks for around $40 and up, but I have no idea what kind of pumps they use in those at this point in time and if you can flip a gasket as easily. At this time I also don't know if hooking multiple smaller pumps would get you better suction or not.
I'd say the Aqua Culture is good for smaller things like beading and small electronics like resistors. But if you want to pick up larger items, I'd look at the Whisper 100 and some suction cups to go with it, which are discussed near the end.
1 Aqua Culture duel air pump.
1 Standard airline tubing. At least 3 feet or longer.
1 Airline T-Valve
1 Air Flow Control Valve
1 Alligator Clip
1 Inflation Needle
2 Small Screws
1 Pen with rubber grip.
1 Pen that fits comfortably in your hand.
Tools and Supplies:
Philips Screw Driver
Drill and Saw or a Dremel Tool
Toothpicks (for applying the epoxy)