The Mylar Shield - Updated Pics and Instructions

[Psychlonic]

The mylar shield is, as far as I know, an original idea of mine based on a very simple, very well known fact about PIR sensors. That is, if you stand behind metal, the sensor won't possibly see you.
Obviously you can't bring along a sheet of metal with you, so the idea is impossible. Even if you could find one light enough, it would be entirely too cumbersome.
My experience with mylar - space blankets - had me wishing for something more effective. Space blankets are scary to work with, because you're always left worried they're going to snag and come off of you, fall off, tear, heat up enough to alert the PIR sensor, and other ideas.
The solution was to make a portable sheet of metal that can be carried on your back almost unnoticed.

Tacking the space blanket to cardboard solves all the issues. If you cut large holes into the cardboard (NOT the mylar) at certain locations to make the shield lighter and easier to fold, you then have a folding sheet of metal, basically. You can attach either Mylar or aluminum foil with equal effectiveness. Attach a handle of some sort to the back, and you can simply crouch behind the shield and walk up on PIR sensors.
Cardboard pieces that are attached until they are the size of a door will fold small enough to cover the area of your back (fits in a small backpack even when using thick cardboard and inefficient folds), which can then be put inside of a low profile backpack or any specially made holder for it. Remember to keep it water tight at all times because if it's soggy it will not stand up.

I highly recommend mylar as it is safer to bend and stretch then aluminum foil is. Aluminum foil works too, but it more prone to ripping and tearing. In either case, you may with to overlay the mylar or aluminum with duct tape to strengthen it against tearing upon unfolding.

[NEW] Pictures of the mylar shield:

http://i.imgur.com/OmeF8.jpg
Here's the shield folded up and placed on a small book bag for size comparison purposes. The black strap is just an elastic keeper to keep it folded tightly. Being cardboard, it has a tendency to want to open itself otherwise.

http://i.imgur.com/KKOah.jpg
This is the shield unfolded to full width. Note the folds.

http://i.imgur.com/GAPn7.jpg
Top view of the shield, showing the folds and demonstrating how it can stand on it's side.

http://i.imgur.com/UipsM.jpg
Here's the mylar side of the shield, completely unfolded. The duct tape applied diagnally is simply to keep the mylar tight against the cardboard, preventing it from pulling away from the tape on the ends or catching and tearing easier.

http://i.imgur.com/856Kk.jpg
This is the cardboard side of the shield. Notice how the shield is basically comprised of cardboard rectangles taped together to form a strong bond. The rectangles have small gaps in between while being tapes so that the shield as a whole is able to fold up easier. The crease down the center can be used to straighten the shield instantly when it isn't hanging down far enough from being folded for long periods of time. It can also keep it standing upright on it's own, for hands-free use when you need both hands in another task.

http://i.imgur.com/nc1tL.jpg
Here the shield is shown on the ground creased down the middle. In a worst case scenario, the shield can be crawled like this to avoid multiple PIR sensors.

http://i.imgur.com/aaRqM.jpg
Shown here is the shield creased and standing upright, demonstrating it's ability to cover you from sensors while you perform a task with both hands.

http://i.imgur.com/GxRHF.jpg
The shield in this picture is in a box configuration. This could be useful for omnidirectional coverage where laying the shield out on the ground and getting under it isn't possible or practical. It could also be used in this configuration in tandem with a mirror when coming out of a ground level entrance to scope for PIR sensors without revealing yourself.

http://i.imgur.com/azyEl.jpg
This is the shield demonstrates another possible configuration for perhaps crab walking through a hallway with sensors on both ends or any other scenario requiring front and back coverage. Note that while the picture was taken with the cardboard out, when using the shield make sure the mylar faces out.


This particular shield is approximately 76" by 27". You can experiment with different cardboard shapes or even materials to optimize the shield and it's ability to fold compactly. This version was made to present to basic idea of the concept and it's ability to completely render PIR useless. It doesn't include a handle, or any special means to see. Peaking your head out is unacceptable. A pinhole could work, and a simple strip of extra cardboard at shoulder height would make a serviceable handle. This shield will give you free reign in front of PIR sensors but caution should still be taken when dealing with multiple sensor types (see my identification threads for more information).

There is still some technique involved in it's use. For example, you can't block ambient heat sources nor can you simply blunder through a door from an area of different temperature if it is within view of the sensor, but other than that it works famously.

The most surefire way to defeat any combination of PIR/ultrasonic/microwave is to get under the shield with the mylar facing out and move along the floor by using your feet to push you along. It will be relatively fast for what you are doing but not fast enough for the ultrasonic nor the microwave sensor to pick you up, and you can move much, MUCH faster than you would be allowed to with a PIR sensor in the area that would otherwise pick up your body heat. You can technically move extremely slowly near a PIR sensor to defeat it, but the rate would be so impractical that the risk of being seen while in the process is huge. Not a smart option. Finally, being low to the ground creates the least risk that your shield will block the sensor's view of heating vents or other heat sources which it already recognizes. Blocking these will create a significant enough change to the sensor that it will open the circuit, sounding the alarm.

As many buildings have only their hallways protected by motion sensors while the individual rooms are protected by magnetic switches in the doors/windows (if anything), this keeps the shield effective since you don't have to use it WHILE entering the building. Simply find a way to get past or around the magnetic switch and into a room, open the door into the hallway just enough to crawl through, and crawl with your shield over you while closing the door behind you.

This can be easier said than done, but once you are in it's all smooth sailing from there if you do it right.

[stealththief]

That's a great idea. I'm gonna try it out sometime. I'll have to get large enough pieces of cardboard. Think it's possible to cut out smaller pieces of mylar and attach them to card board that is folded into smaller sizes?

[Psychlonic]

That's sort of the idea, I'm trying to find fucking batteries for my camera right now actually. Basically, I took a bunch of duct tape and smaller cardboard pieces to make what you'd call a cardboard blanket, then attached the mylar. I used relatively large pieces, and of heavy cardboard at that, and mine still folds down to about the size of a large textbook. Smaller results should be easily achieved using thinner cardboard and smaller pieces.
As soon as I find some god damn AA batteries though I'll snap the photos and upload them.

[stealththief]

Sounds good I look forward to seeing it.

[Dethkreep]

Really good idea. I'd make one if I really had a situation I knew I would use it in. I'm a little confused on the design though, so pics would be appreciated.

[Psychlonic]

I know I know. I've got one of those shitty digital cameras (since I never use it really) that NEEDS brand new, high quality batteries else it thinks the batteries are dead for whatever reason. Even though they still typically have over 2/3 of their charge.
At the latest, I'll have some up Monday since I got to run errands anyways and I'll probably pick up a pack of them then. In the meantime, I guess cross your fingers that I run across a remote, flashlight, SOMETHING with new batteries in it around my house.

[Psychlonic]

Updated first post. Enjoy.

[stealththief]

Great pics, it cleared up a lot i was thinking about.

[Psychlonic]

Of course. For anyone else, I urge you to check out my topic on the shield at TOTSE, especially if you have doubts it will work. I present solid facts and theory backed up with credible references for most of what I say, and if anyone wants references where there isn't one, just ask. I spent the time on this topic to get this idea out and about, the "PIR is undefeatable" myth needs to end, so I plan on promoting this idea heavily and proving it's worth against anyone who says otherwise to make sure that happens.

[Psychlonic]

Re-uploaded pictures, more details.

[CXDBrightSide]

Very nice! We have a PIR sensor set up inside the office near the fireworks stand I work at in the summer, I'll have to try this out.

Oh, and I know what you mean by moving insanely slow. The sensor covers about 25 feet and it took me well over 20 minutes to successfully get around it without it going off. It is especially difficult because it's up high facing down and the door (target) is about 3 feet in front of it and opens towards it.

[Shade]

Could you make it into a pop-up shield of sorts, with a wire frame or something?

[Xanatos]

Wouldn't work. Modern security systems nowadays have ABP, which blocks popups.