Magnetic Levitation Petri Dish Documenter

Bacteria culturing can be a rather tedious process as I found out after doing some bacteria culturing. It was rather amusing that all other processes were carried out with specialised tools and methods but when it came to recording the colonies, the only apparatus used was a black sheet of paper, a phone camera and a somewhat shaky hand. With all these combined, the only product was a grainy and blur-ish picture. As such I set out to create an apparatus that could improve the entire process.

What you need...

Materials:

Acrylic ( I used 3mm sheets, clear acrylic is recommended )

8mm triangular acrylic strip

Aluminium Tape ( Used to insulate Air Ducts, but in this instance used for its reflective surface)

LED Strip (12V, 1A)

Wires

Electrical tape (PVC electrical insulation tape)

Magnets

Adhesive Magnetic Strip (Optional)

Power Adaptor

Acrylic Glue

Spring tension paper clips

Strip Board

Equipment:

// If you can use any other type of equipment for the job please do so.

Laser cutter

Soldering Iron

Hot Glue Gun

Strip Heater (Acrylic Bender)

Software used:

AutoCad 2015

Corel Draw V7

Step 1: First Things First...

All drawings have been uploaded so feel free to use them.

Take not of the notes below detailing things you may want to edit...

[ Top and base of viewer ]

Since this document-er is going to be as compatible to all phone models, a hole of 15mm (dia) was used.

All lines are to be cut.

[ Stage v1.2 ]

Since the size of the petri dishes used in the laboratory I do research in can range between 100-110mm (dia), the engraved circle on the stage was set to 110mm.

The two inner vertical parallel lines are engraved to ensure clear distinction on where to bend the acrylic.

[ Side supports annotated ]

All annotations are to be engraved.

[ Magnetic Slider ]

All inner vertical lines to be engraved and serve as guides for bending.

All sizes can be adjusted accordingly if you require a more specified shape or size.

Step 2: Assembly

Once all the acrylic parts have been cut out, the assembly begins!

It should be quite apparent to where the pieces fit. The only pieces that are not permanently attached to the main body of the viewer are the magnetic slider and the stage.

First off, attach the aluminium tape to all the inner-facing surfaces (side panels, back panel & top panel (optional)). This will first of all block all external lights from entering the inner cavity from the back, left and right side of the viewer. Secondly, it can help to reflect the white light generated from the LED strip inside. This is done as external lights can cause, say bacteria colonies to be captured in a different colour. This should/must be done with acrylic that is anything other than clear acrylic.

A tip in ensuring that the tape is laid as smoothly as possible is to remove just a small strip of paper backing on the tacky side of the aluminium tape and position it. Then use a ruler or any flat and straight object that does not have any sharp edges and slowly push the tape across to surface of the acrylic. The paper backing should slide off just fine.

Once the sticking has been completed, assemble the main body of the viewer ( Top and base, back panel, side panels and side supports ) and stick the big boy together with acrylic glue.

Remember to cut the 8mm acrylic triangular strip so that you can mount the LED strip on it. The length in this model was 155mm long. It was stuck to the one of the corners inside the cavity using hot glue.

Once the glue has dried, you can start on the circuit.

Step 3: Circuit

The circuit is relatively simple, by simply just connecting the positive side of the LED to the positive node on the socket and same goes for the negative side. One small strip is more than enough to light up the cavity

Step 4: Stage and Magnetic Slider

Stage:

By heating and bending along the engraved lines, a " [ " shape can be formed. The two little circles on the protruding sides will be where you stick the magnets. Do note that you stick the magnets in the inner side of the protruding "legs". Once done, your stage is ready to go!

As for the magnetic slider, heat the area between the two engraved lines at the center of the slider. Then take a piece of acrylic and fold the heated section into two equal halves with the acrylic piece (3mm thickness) between the two halves. Then heat the two other lines on the respective halves and bend them in opposing direction at a 90 degree angle. Once done, position the magnets on the slider and stick them on!

Step 5: Final Touches

Mount the LED strip and run the wire to the back of the main body and stick it down with the PVC insulation tape.

Test the sliders to ensure their movement up the side supports are smooth. If they aren't, smoothen the insides of the slider with sand paper.

Now all you have to do is connect up to a power supply and it is ready to go!