Testing

New Additions To the Initial Sketch

The Liquid Crystalline Lens

Solving the "Hardening Issue" of the Ooho

With the original method of creating the ooho, there were multiple problems. The first problem was that after a while, whether you put it in calcium lactate water or water, the inside would harden and the ooho would turn opaque. If the lens was kept this way, the light wouldn't be able to pass the lens correctly, and even if light passed, the focal point wouldn't be clear enough to be seen because so few light rays passed. The first method I used to try to fix this problem was taking out the sodium alginate from inside the ooho. I used a syringe to take the sodium alginate out, and put water instead. The problem with this method was that the syringe made a small hole that would make water leak out of the ooho. To mitigate this, I tried to add calcium lactate over sodium alginate to create a new membrane over the hole, but this didn't work.

Using Super Absorbent Polymers: Solving the Physical Disadvangates of Ooho

This new lens is made out of sodium polyacrylate(-[-CH2-CH(COONa)-]n-), an odorless, grainy white powder. Its most impressive property is its ability to absorb large amounts of fluid, up to 800 times its volume of distilled water and lesser amounts of other liquid mixtures.

The problems listed above about the ooho lens aren't present for this lens as if it stays moist, it will stay the same. Because the liquid lens is going to be in a lens barrel, which is a confined space, the moisture of the lens isn't going to escape out of the lens.

The "Pressing" Mechanism

Adding Rubber: Having More Control Over the Motor

Because the motor I had's speed couldn't be controlled, I had to come up with a new way to control the motor speed to the speed I want it to be. The method I used to slow down the speed of the motor is by increasing tension using a rubber band. With the rubber band, the speed of the motor decreased dramatically, giving me more control over the speed of the motor.

With the rubber band attached, there were some obstacles to go over. Because the tension was so high, there were times were the motor won't turn at all. The amount friction created by the tension of the rubber band was a big obstacle to go over.

Reinforcing the Ceiling of the Machine

Because the heavy "pressing mechanism" was on the ceiling of a relatively weak cardboard box, after some time, certain problems began to arise. One of the biggest problems would be with the gear of the mechanism. The gear would be simply out of place and not functioning.

To reinforce the ceiling, screws were added to increase stability, an additional piece of cardboard was added to the ceiling to make it more robust, and the tape was added to make sure all the new additions stayed in place.

Getting the Refractive Index and Focal Point of the Lens

When the Lens Isn't Pressed

Using Snell's Law to Get the Refraction Index of the Lens

According to Snell's Law,

Because we have three of the four values, if we plug in the values we know, we can get the fourth value. We know from the image that the incident angle is approximately 70.5 degrees, the refracted angle is approximately 53 degrees, and the incident index is 1.0003 because the first medium is air, and its refractive incident is 1.0003. After we plug in these values, we are able to know the refracted index, which is the refractive index for the lens.

The Refractive Index of the Lens: 1.18

Curved Surface Refraction Formula: Finding the Focal Point

If we plug the information we got from above into the curved surface refraction formula,

We get the equation

if we say that the object is 30cm away from the lens.

If we solve the equation, we get the lens' distance from the focal point, which is 25.3cm away from the lens.

25.3cm isn't the real focal point though. As shown in the image above, when the light comes out of the lens, the medium changes again, and light refracts again. Thus, the distance we got isn't the "real" distance to the focal point.

This time, the outside medium is going to be the refractive medium, meaning that the refractive angle is going to be formed in the outside medium which is air. Plugging in the values like the previous equation gives us

If we calculate this equation, we get 7cm. This means that when an object is 30cm away from the lens, the light rays are going to meet 7cm behind the lens.

2. When the Lens Is Pressed

Using Snell's Law to Get the Refraction Index of the Lens

According to Snell's Law,

Because we have three of the four values, if we plug in the values we know, we can get the fourth value. We know from the image that the incident angle is approximately 45 degrees, the refracted angle is approximately 37 degrees, and the incident index is 1.0003 because the first medium is air, and its refractive incident is 1.0003. After we plug in these values, we are able to know the refracted index, which is the refractive index for the lens.

The Refractive Index of the Lens: 1.18

Curved Surface Refraction Formula: Finding the Focal Point

To know at what distance an object will be when its focus point is 7cm behind the lens, we have to write down the equations first like how we did for the lens that didn't press. The two equations are: