Conversations in Science: Experiments with Kids
If you search the Internet, you will find many different pages and examples of people that have turned their smartphones into holographic projectors. All of them work on the same principle: reflection and virtual images. Seeing how simple these projectors were to construct, I couldn't resist making one of my own and sharing it with you all.
To create your own holographic projector, you'll need the following:
- Smartphone or tablet
- Clear plastic from CD cases
- Tape
- Box cutter or craft knife
- Template for pieces
- Marker
Step 1
The template you need is based on an equilateral triangle with the top cut off and is shown in the image below. There are two sizes shown: the one on the left is for mobile phones, where the one on the right is the largest unit that can be made from a CD case.
Templates for homemade holographic projector pieces. To convert to inches, divide the measurements in centimeters by 2.54.
Mark the edges of your shapes onto the clear plastic of a CD case, then cut them out. You'll need four identical pieces.
Step 2
After you have your template, mark the plastic, then score straight lines with a box cutter. It will then be possible to snap out the pieces. (Hint: Score the line several times, then flip the piece over and bend the cover in the opposing direction for a clean snap.) Make four pieces of identical size and shape.
Step 3
Tape the pieces together. Ensure that the openings are as square as possible.
Carefully tape together the pieces to form a pyramid structure. Make sure that the openings are as square as possible to the unit so it will stand up properly. (Hint: When done, run a thin layer of tape around the edges so you don't scratch the surface of your phone or tablet.)
Step 4
Download any number of videos from YouTube that you can used for your hologram. Or download an app that will allow you to use your own videos. However, do keep in mind that any videos that you use will be the reflected mirror-image in your hologram.
The Science
The holographic image is actually a reflected image off the 45 degree surface slanted toward us.
The holographic image that we see using our homemade projectors is actually the reflected image that is seen reflected off the 45-degree surface that is slanted toward us. The image, from our perceptions, is situated behind the plastic, appearing in the middle of our projector unit. The image is not real, but is virtual.
All features are reflected on the side, but the image appears back to front.
However, one should note that we see a mirror-reflected image, i.e. any writing will be reversed. This is because of the angles involved. Like any mirror reflection, features from one side of an object will be seen on the same side of the image, just flipped front to back.
Regardless, playing around with holograms is lots of fun; the young and old alike enjoy the effects. (My husband loves sitting there watching a hologram while enjoying his breakfast.)
For more information about the homemade holographic projector and to see it in action, check out the special video edition of Conversations in Science: Experiments with Kids on the YouTube channel. (Video link is also shared below.)