logo

College of Engineering Unit(s): 
Chemical, Biological, and Environmental Engineering

Team: 
Heoniya Sharabarin, Arthur Finstad, Tanner Rakos and Michael Arellano

Project Description: 

Project Summary - Bioengineers:
Every year, millions of pounds of food and medical supplies are thrown out due to either improper labeling or lack of a distinct label. These labels are usually composed of small, black text with messages such as “Use before date” that can easily be missed or disregarded, and so are insufficient in clearly communicating a product's viable shelf-life. To address this issue, we have designed a color changing label that can be tailored to any product with a lifespan of up to two years. The label is composed of three layers: an indicator, activator, and an intermediary barrier layer. Color change is achieved by an acid-base reaction between bromophenol blue sodium (BPB-Na) and citric acid (CA). In aqueous solutions at room temperature, alkaline BPB-Na solutions will change from purple to red at pH 4.6 and from red to yellow at pH 3. An indicator layer is made from a permeable hydrogel with dissolved BPB-Na, and similarly an activator layer is made of a hydrogel dissolved with CA. To initiate the color change, the activator layer is firmly pressed onto the indicator layer, at which point BPB-Na and CA will slowly diffuse through the hydrogel matrix and begin to react. The rate of this reaction can be controlled by altering the initial concentrations of BPB-Na and CA; in addition, if sodium carbonate (SC) is added to the indicator layer, the BPB-Na + CA reaction will be delayed as the CA will react first with SC in a more favorable reaction. To further reduce the reaction time, an elastomer barrier layer can be inserted between the indicator and activator matrices prior to initiation. This layer will further slow the migration of molecules through the layers, to a max period of two years. 


Project Summary - Adults (non-engineers):

Every year, people risk their health from consuming expired medicine and lose money from throwing it away, simply because they did not know it was expired. We decided to develop a product that would easily inform people about their state of their medicine with a slight glance or a quick scan on a smartphone. The product is small, cheap, easy to use, and informative. Here is how it works. When you purchase medicine from the pharmacy or store, it will come with a small green square on the side. Next to this square will be a QR code. If you have any questions about the medicine, doses, side effects or anything else, you can scan the code and it will link to all the information you need. If you want to know if your medicine is safe to consume, you can look at the colored square next to it. If the square is green it is ok to consume. As it turns yellow and finally to red, you will know your medicine is expired and should be disposed of properly. This little square is not magic, but in fact it’s a safe and simple chemical reaction. Over time, our product goes through a chemical pH reaction; as the chemicals diffuse through the product, the concentration increases and the label changes color. No more looking for a poorly printed label. No more searching aimlessly for information that should be easily accessible. With the color changing expiration label, all of these problems will be no more. 

Project Summary - Grade School Students:
Have you guys ever opened a jug of milk and found it to smell bad and have solid bits in it? Or the fruits on your counter at home, have you ever noticed how apples and bananas slowly turn brown over time? That is called product expiration, and the same thing can happen to your headache medicines and gummy vitamins, but it takes a lot longer for this to happen when compared to a banana browning. Since the medicines don’t change color or smell when they begin to go bad, it can be difficult to tell if it is safe to use the medicine because using an expired medicine could make you sicker! We decided to make a sticker that sticks on the outside of your vitamin bottle and tells you if your little pills are safe or not. Our sticker is stuck to the bottle right after the medicine is made, and the sticker starts off as a bright green color. Over time the color of the sticker changes from green to yellow to red. Green means you can eat your gummies safely, yellow means they are still safe but you should ask your parents to think about getting more the next time they go shopping, and red means that you should not take your medicine because it could be dangerous. As I’m sure you have learned in science class or seen in some science YouTube videos, there are certain things that when put together, create a reaction like changing color, creating foam, or even exploding! Those materials the scientists put together are called chemicals. There are two main chemicals used in our sticker. Have you ever seen how sugar or salt seem to disappear after a while when you put them in water? In a simplified way, that process is called diffusion. Our sticker has a little bit of a first chemical that acts as the water, and a little bit of a second chemical that acts as the sugar. Once the chemicals are mixed together, the second chemical slowly diffuses into the first chemical and causes it to change color. 
 

Project Communication Piece(s): 
AttachmentSize
PDF icon Color Changing Medical Expiration Label Description315.93 KB
Project Communication Pieces do not open in a new window. Please use your browser's back button to return to this page.