|30||Bubble Tea Machine
- Emily Hall (emilydh2)
- Tracy Tang (tracymt2)
- Saisita Maddirala (smaddi4)
Bubble tea shops are hugely popular on our campus. While incredibly tasty to drink, the manual labor of making numerous teas can get exhausting over time. As the bubble tea fad grows, the price grows just as much, costing at least $6 for a well-made drink. While it may not seem like a lot of money for a one-time purchase, the expense certainly piles on as consumers continue to buy their favorite drink.
An immediate solution would be to simply make your favorite drink at home, however, this greatly increases the manual work that one would need to do. Between needing to mix all the ingredients and boiling the boba, it can get tedious when making the drink frequently. College students are busy and broke and just want their boba without it being too expensive or tedious.
It would be nice to have a vending machine type of structure that creates a drink for you but is placed at a convenient location for public use. This would greatly decrease the manual labor that is required to create the drink, while also making it cheap for consumers to buy, without needing to feel guilty.
Our team is proposing a Bubble Tea Vending Machine. This machine will allow the user to just press a button, and the machine will make and dispense the bubble tea. The machine will have large reservoirs for milk, tea, and syrups. It will boil and store the boba. It will dispense all the ingredients in the appropriate quantities each time someone buys a drink using a button pad. To dispense, we will use water pumps to get exact quantities.
The user will interface with the machine via a small button board that will be on the outside of the machine. The board will have buttons for selecting the size and flavor of the drink, etc. The user then presses start. (We will have the boba be dispensed first to prevent splashing.) The machine will only start if there is a cup present that can be identified via a load sensor and a start button is pressed.
After the boba is boiled, we will need a plan for storage. Our approach is to store it for as long as possible in simple syrup. We will need to do some testing to figure out how long this is, but from research we think it’s around 10 hours. At this point, new boba will be made. New boba will also be triggered to be made when the boba storage is low, using a weight sensor. Then, the boba will be removed from storage and into a garbage holder that will need to be emptied very occasionally.
At the top of the casing, there will be reservoirs for the ingredients: milk, water, syrups, and boba. From the reservoirs, there will be tubes that the liquids will pass through and that open above the cup. Valves will control when the ingredients are allowed to pass into the tubes. The boba will pass through a larger opening and drop directly into the cup.
Required parts: Solenoid valves, plastic reservoirs, plastic tubing
The ingredients need to be kept cool. In order to do this, we will build a small refrigeration unit around the ingredients using styrofoam and a Peltier Cooling Unit. See the link below about setting up a device like this.
Required parts: Peltier Cooling Unit
This element will control the opening and closing of the valves depending on the input from the buttons and the load sensor beneath the cup. The load sensor will allow the device to decide when to close the valves based on the amount of ingredient that has already been dispensed. The amount will depend on the size of the drink. The microcontroller will also monitor the amount of boba and the time that has elapsed since the last batch of boba was made. If the boba has sat too long then it will be evacuated out of the system. The microcontroller will then initiate another cooking cycle of the boba.
Required part: microcontroller such as an Arduino, or a raspberry pi.
This element will be made of 9 push-button switches. The buttons will represent the size of the drink (3 options: 12oz, 16oz, 20oz), the flavor of the drink (3 different flavors), “start”, “no boba”, and “cancel.” The user will select the size of the drink they want and a flavor. They can choose another special instruction such as “no boba.” When these are selected the microcontroller will make the appropriate adjustments when controlling the valves. If the cancel button is pressed, all previous selections will be ignored. Once the start is pressed the machine will begin to measure and mix the drink. Any buttons pressed during the making of the drink will be ignored.
Required Parts: push-button switches
**Cup Load Sensor:**
There will be a pad where the cup will go. Underneath this pad, we will have a load sensor that measures how many ounces are dropped into the cup. As the liquid is dispensed into the cup, the load sensor will alert the microcontroller of the increase. This will allow the microcontroller to know when enough ingredients are placed in the cup (and to close the valves).
Note: We may need a signal amplifier with our sensor to be able to measure the ounces in a cup.
The boba will rest in a tank that can be heated with a heating element. When fresh boba needs to be prepared the tank will be filled with water and heated. When the water is boiling the boba will be dropped into the tank. The microcontroller will decide how long to cook the boba for. Once the boba is finished cooking the tank will stop being heated. The water will drain out and then simple syrup will be dispensed into the tank.
**Boba Load Sensor:**
There will be a simple kitchen scale to check that there is enough boba for at least a few drinks. We will then make and add more boba.
This machine will be plugged into the wall via a surge protector that all elements will be plugged into.
**Criteria for Success:**
- Store boba in such a way that its texture is preserved.
- Dispense the correct amount of tea and milk according to the selected cup size.
- Dispense the correct flavor according to the button press.
- Failure proof if the user presses buttons randomly. (Won’t begin to process commands until start is hit), (Won’t recognize any new button presses until the drink is finished), (Only record the last button that was pressed )