7/2020: STEM + E

 STEM stands for Science, Technology, Engineering, and Mathematics. Most students are familiar with STEM to design the technical work, but they forgot to consider the use of one more E, Economics.

I had a chance to do the STEM work called a newspaper water tank challenge. This project taught me how to create, adapt, and fix the problem with limited resources. The supervisor assigned the problem to make a newspaper water tank that can achieve the maximum ratio of water volume after 3 minutes to the tank weight. There is a given 18 g materials to make a tank to hold a maximum of 200mL or 200 g of water within 3 minutes on the flat horizontal surface without any other supports except the materials given. It is even more challenging that the materials are a 57.5 x 44 cm sheet of newspaper, 80 cm masking tape, and 4 popsicle sticks only. 

I have to trade-off between the volume of held water within 3 minutes and the weight of our newspaper water tank because the winner is the one who gets the highest number of the held water volume after 3 minutes divided by the weight of the water tank.  So, the winner may not be the one that can hold the highest amount of water collector, the winner will be the best balancer.

I identified and prioritized the primary and secondary research and analyzed the existing products. The results of the experience about the newspaper water tank project showed that the water volume held by most paper water tank high-level groups ranged from 140-170 mL (no 100% perfect ) because the newspaper was a very good absorber.newspapers absorb water quickly when compared with other papers  Most of the water was absorbed by the paper and leaked, 44% and 28% respectively.  The water tank should not too big and not too heavy to reduce the weight of the tank while it will be able to hold the water volume after 3 minutes at a high-level group. Vista think newspaper water-tank-engineering 

Most oil and chemical tanks in the real world project use sphere shape for the highest safety. It means that this shape is a very strong structure. The even distribution of stresses on the sphere’s surfaces, both internally and externally, generally means that there are no weak points. Sphere; however, is much more expensive to manufacture than cylindrical tanks. Introduction to Spherical and Cylindrical Pressure Wermac

I also analyzed the surface area of the same volume of 3 different shapes of the water tank. The water tank with less surface area will be less material and less weight. 

The surface area of 200 mL tank is as following,

Spherical tank  =    163   cm2           

Cylindrical tank =   161   cm2

Rectangular tank =  180  cm2

Because of no top wall of the water tank in this assignment, the surface area of the spherical tank is a bit higher than that of the cylindrical tank.  However, after reviewing the existing products, I learn that there is an Origami Paper Power Bomb  Origami Paper Power Bomb that I can apply to make a paper water tank with a single part (no joint and lower overall weight) and the product looks similar to the sphere shape, which is the very strong shape, so the tank will hopefully less leakage.  Rectangular shape may not be the right choice because it needs more material to hold the same amount of water compared to a cylindrical and spherical shape, so more weight. There are many edges, so it needs more supporters to protect water leakage. 

Next step, I designed a suitable size, sphere shape without a joint newspaper water tank to maximize the ratio of held water volume after 3 minutes to the weight of the tank.

Then, I built the tank and tested it. The newspaper water tank design was very successful. The resulting score (52.9), was far above other groups.

The design was successful because I

1. Clearly understood the problem (trade-off water volume with tank mass),

2. Studied the existing products and other failures,

3. Applied STEM + E (Science, Technology, Engineering, and Math) + Economic

 Science: I studied which kind of shape is the best for making a tank? (sphere, cylinder, rectangle)

 I studied the property of the newspaper about absorbing water.

Technology: I applied the Origami paper bomb to be the key success tool.

Engineering: I followed the engineering design process and care about all steps, particularly taking out the water from the delicate tank after 3 minutes.

Mathematics: I justified our design by using geometry math (volume and area calculation), and designed a suitable tank size, which is the key success. 

Economic: I balanced the water volume(no need to be the best) and tank mass.

   

    

200 mL Water was exactly fitted to our design tank size.

    
                                                                                            

I observed that all other designers used STEM, but not Economics. They tried to make a strong tank and hold maximum water. So, training STEM must include one more E, Economics.