Project Development

1. Our Team Chemical Device

For our project, we worked on creating a functional tea maker. Its main objective is to combining the heating and infusing process of brewing tea into a single machine, therefore making the tea preparation process more convenient and simpler.

In order for it to work, it requires a certain volume of water and a measured amount of tea leaves in order for it to work. The hot water poured on the tea leaves in a tea basket/infuser attachment allows the tea leaves to steep. Different tea types have different brewing requirements, as each tea type has their own optimum brewing time and brewing temperature to extract the best flavour.

By conducting some secondary research online, we found that there were some issues plaguing the current models of tea makers in the market. Firstly, tea makers can be quite expensive, especially those with a lot of different functions. Next, modern tea makers tend to be made up of more intricate parts, making them more complex and more difficult to use. In addition, this may also make disassembling the tea maker for cleaning and maintenance more tedious. Lastly, there is no way for the machine to notify its user when the tea is ready.

Thus, the tea maker we are making should be able to address these issues. On top of that, it should also be able to steep the tea at the desired temperature within the desired amount of time. The tea should be prepared to have the desired taste, texture and aroma.

Figure 1: Sketch of Tea Maker

Figure 2: Dimensions of Tea Maker

2. Team Planning, Allocation and Execution

Our team consists of 4 members: Nick (Me) as the CEO, Kieran as the COO, Anwar as the CFO and Xavier as the CSO.

In our task allocation, I was in charge of designing the tea maker, as well as producing the codes to be used, Kieran was in charge of drawing the different parts to be 3D printed or laser cut in Fusion 360, Anwar was in charge of booking the different facilities and assembly of the final product, and lastly Xavier was in charge of wiring the different components together.

Figure 3: Bill of Materials (BOM)

Figure 4: Completed Gantt Chart

3. Design and Build Process

Part 1: Design and Sketching of Tea Maker (done by Me)

In the design process, I carried out a parts-whole analysis of the tea maker. This allowed me to identify the different parts of the tea maker that were essential to its function. I was able to explore the different roles that these parts played, as well as what would happen if the part was removed.

Parts-Whole Analysis

Servo Motor with Stirring Rod

• Purpose: It is used to stir the mixture of water and tea leaves.
• Rationale: It ensures that there is even steeping between the water and tea leaves.
• Implications of Missing Part: The water and tea leaves would be unable to mix evenly. The end product will not be well-mixed.

Temperature Sensor

• Purpose: It is used to measure the temperature of the water and tea leaves mixture.
• Rationale: It allows the tea to be brewed at the desired temperature.
• Implications of Missing Part: The user would be unable to tell if their tea is being prepared at the correct temperature.

LCD Display

• Purpose: It is used to display important information, such as tea temperature and time passed since start of tea preparation.
• Rationale: It allows user to know the progress of tea brewing, as well as how much more time is required to complete the process. It also displays the temperature of the tea, so that the user can know that the maker is working fine and preparing the tea at the correct temperature.
• Implications of Missing Part: The user would be unable to tell when their tea is ready for consumption, as they do not have an estimate of how much more time is required for their tea to finish brewing.

Buzzer

• Purpose: It will emit noises at preset timings to alert the user that the tea is complete.
• Rationale: The user does not have to constantly check on the progress of the tea, and they can go ahead to carry on with their day, and only return to drink their tea when the buzzer signals to them that their tea has finished brewing.
• Implications of Missing Part: The user would be unable to tell when their tea is ready for consumption, especially if they are away from the tea maker for extended periods of time.

Circuit Board

• Purpose: It connects all the components together to a power source.
• Rationale: It connect all components to an electrical source and ensures that every part has enough power to function.
• Implications of Missing Part: The tea maker would be unable to function, as the parts would not have any electricity flowing through them.

Possible Improvements or Combinations

• The servo motor can be coded such that the stirrer speed is at its highest setting for better mixing.
• The LCD Display can be coded to work together with the temperature sensor to display the temperature being measured by the sensor.
• Instead of a separate buzzer, we can use the one already integrated in the Arduino Maker Uno. This will help reduce the amount of wiring required.

The Sum of Its Parts: The temperature sensor measures the temperature of the hot tea being brewed, while the servo motor mixes the tea leaves and water, brewing the tea. Since the user is unable to monitor the process of the tea brewing, the LCD display will allow them to estimate the amount of time left before the tea is ready. When the tea is ready, the buzzer will sound to alert the user. All components in the tea maker are connected together to the power source by the circuit board.

After the Parts-Whole Analysis, I applied the 3-Step TRIZ process to generate possible improvements that can be implemented onto our tea maker.

TRIZ

Option 1: Design the tea maker to have the ability to continuously heat up the tea to a set temperature. If the user is busy with something else and is unable to attend to it, he can still return to a cup of tea that has not become lukewarm or cold.

• Advantage: This will keep the tea warm at the desired temperature until the user is ready to drink it.
• Disadvantage: It will result in a lot of energy lost, as the tea will continuously lose heat to the surroundings, and more energy will be required to maintain the tea at the desired temperature.
• Technical Contradictions: Temperature (17) and Loss of Energy (22)
• Inventive Principles: Another Dimension (17), Skipping, Quick Mode, or Pace of Realisation (21), Changing State, Parameters, Properties of Materials (35) and Strong Oxidants (38)

Option 2: Design the tea maker to be able to steep a wide variety of tea. Different kinds of tea require different steeping times and different water temperatures. For example, black tea is best prepared at 208°F (98°C) for 3 to 5 minutes, while green tea should be prepared at 175°F (80°C) for 2 to 3 minutes.

• Advantage: This will improve the versatility of the tea maker, as it can make various different types of teas to match the differing tastes of different users.
• Disadvantage: This may cause the tea maker to be more difficult to use, as the user has to constantly change the settings to fit the concentration and type of tea that he wants.
• Technical Contradictions: Adaptability or Versatility (35) and Ease of Operation (33)
• Inventive Principles: Division (1), Embedded Structures (7), Dynamics (15), Excessive or Partial Action (16) and Discarding and Recovering (34)

Option 3: Design the tea maker to be fully automated. The tea maker can prepare the tea without requiring the user to lift a finger. For example, instead of having to manually load the tea leaves into the cup, the tea maker can be connected to a tea leaf storage and dispenser, which will load the tea leaves into the cup when the user wants some tea.

• Advantage: This will make the tea maker easier to use, as the user can simply key in an input to start the tea maker, and the tea maker will execute the steps to make the tea.
• Disadvantage: This will cause the tea maker to be more complex, as more components will be needed to make the tea maker fully automated, and some small components may also need to be upscaled as well.
• Technical Contradictions: Ease of Operation (33) and Device Complexity (36)
• Inventive Principles: Equipotentiality (12), Another Dimension (17), Copying, Imaging Principle (26) and Colour Changing (32)

Option 17 appeared more than once, hence it will be selected for implementation. The other options that are suitable for implementation are option 15 and option 35.

Interpretation and Contextualisation

From option 15, the idea we came up with was to allow the height of the tea maker to be adjustable in order to accommodate different cup sizes. From option 17, our idea was to have the storage for the tea leaves to be built-in above the tea-brewing station. This storage section can be divided into different compartments to store different types of tea leaves. Lastly, from option 35, for the material of the cup, we can use a material that has a lower thermal conductivity, or a cup that is insulated to reduce heat loss to the surroundings. For the material of the heating element, we can choose a metal that has a lower specific heat capacity to decrease the energy requirements.

This is our original design for the tea maker after the TRIZ process. Due to some parts being too complex to code at our current skill level, we had to remove these parts, such as the input buttons and the dispenser. We also had to remove the heating element due to safety reasons. Thus, we used hot water instead.

Thus, we had to produce an updated version of our tea maker, one that was more suited to our skill level. The sketches and specifications for the updated tea maker can be found in Figures 1 and 2 above.

Figure 5: Product Specification Table

Part 2: Design of Parts in Fusion 360 (done by Kieran)

Link to blog: https://cp5070-2021-2b01-group2-kieran.blogspot.com/2022/02/project-development.html


Part 3: Assembly of Parts (done by Anwar)

Link to blog: https://cp5070-2021-2b01-group2-anwar.blogspot.com/2022/02/project-development.html


Part 4: Wiring (done by Xavier)

Link to blog: https://cp5070-2021-2b01-group2-xavier-chua.blogspot.com/2022/02/cpdd-blog-project-development.html


Part 5: Coding (done by Me)

//I2C bus support
#include <Wire.h>
//I2C
#include <LiquidCrystal_I2C.h>
//OneWire bus suport
#include <OneWire.h>
//DS18B20 temperature sensor support
#include <DallasTemperature.h>
//DS18B20 sensor pin
#define ONE_WIRE_BUS 2

#include <Servo.h>

#include <pitches.h>
int buzzerpin = 8;
unsigned long timer1 = 119000; // 2 min
unsigned long timer2 = 179000; // 3 min
unsigned long timer3 = 239000; // 4 min
unsigned long timer4 = 299000; // 5 min
unsigned long TimeNow;
bool startbuzzer=false;
bool startedbuzzer=true;
bool startedbuzzer2=true;
bool startedbuzzer3=true;
bool startedbuzzer4=true;

// Setup a oneWire instance to communicate with any OneWire devices
// (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);

Servo myservo; // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0; // variable to store the servo position

LiquidCrystal_I2C lcd(0x27,16,2); // set the LCD address to 0x27 for a 16 chars and 2 line display

// notes in the melody:
int melody [] = {
NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5, NOTE_C5
};

// note durations: 4 = quarter note:
int noteDurations [] = {
4, 4, 4, 4, 4, 4, 4, 4
};

void setup()
{
lcd.init();
lcd.backlight(); //Turns backlight on
sensors.begin();

myservo.attach(9); // attaches the servo on pin 9 to the servo object

startbuzzer = true;
// buzzer code (for loop)
}

void loop()
{
sensors.requestTemperatures();

//Read first sensor
float temp = sensors.getTempCByIndex(0);

//Print first sensor results
lcd.setCursor (0, 0 );
lcd.print("T: ");
lcd.print(temp);
lcd.print(" ");

// print the number of seconds since reset:
lcd.setCursor (2, 1 );
lcd.print(millis() / 1000);

//Wait 0.1 sec
delay(100);

for (pos = 0; pos <= 0; pos += 1) { // goes from 0 degrees to 180 degrees
// in steps of 1 degree
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(0); // waits 15ms for the servo to reach the position
}
for (pos = 0; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(0); // waits 15ms for the servo to reach the position
}

unsigned long currentTime = millis();
if (startbuzzer){
TimeNow = currentTime;
startbuzzer = false;
startedbuzzer = true;
startedbuzzer2 = true;
}
if (startedbuzzer){
if((unsigned long)(currentTime - TimeNow >= timer1)){
buzz();
startedbuzzer = false;
}}
if (startedbuzzer2){
if((unsigned long)(currentTime - TimeNow >= timer2)){
buzz();
startedbuzzer2 = false;
}}
if (startedbuzzer3){
if((unsigned long)(currentTime - TimeNow >= timer3)){
buzz();
startedbuzzer3 = false;
}}
if (startedbuzzer4){
if((unsigned long)(currentTime - TimeNow >= timer4)){
buzz();
startedbuzzer4 = false;
}}
}

void buzz(){
// iterate over the notes of the melody:
for (int thisNote = 0; thisNote < 8; thisNote++) {

// to calculate the note duration, take one second divided by the note type.
//e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
int noteDuration = 1000 / noteDurations[thisNote];
tone(8, melody[thisNote], noteDuration);

// to distinguish the notes, set a minimum time between them.
// the note's duration + 30% seems to work well:
int pauseBetweenNotes = noteDuration * 1.30;
delay(pauseBetweenNotes);
// stop the tone playing:
noTone(8);
}
}

This is the code that I used for the tea maker. It consists of three separate codes combined into a single file. The individual parts that were coded are the temperature sensor with LCD display, the servo motor and the buzzer.

Part 6: Integration of Parts and Electronics (done by everyone)

This is the file for the stirrer that is attached to the servo motor. It was 3D printed.

This is the file for the tea cup that was used in the demonstration. It was 3D printed.

This is the file for the tea cup holder that is used to house the tea cup during tea preparation. It was 3D printed.

This is the file for the tea leaves tray that is used to store tea leaves. It was 3D printed.

This is the file for the different parts of the tea maker's main body. It was laser cut and glued together.

Figure 6: Final Product (Front View)

Figure 7: Final Product (Side View)

Figure 8: Final Product (Top View)

Video 1: Made in Heaven - The Gold Experience

Figure 9: Hero Shot with Final Product

4. Problems and Solutions
We encountered several problems during the entire process of the project.

Firstly, when we were performing the 3D printing, we found out that the tray we had intended to use to hold electrical components was printed too small. Thus, we redesigned the entire section to be laser cut instead. Next, some of the joineries for the 3D printed parts were wider than expected and did not fit through the holes, thus there was no way for them to connect to one another. Our solution was to redesign the connection holes to be bigger to allow for more leeway, so that there is extra space for the joineries to fit in.

Next, when we were performing the wiring for the different electrical components, we found that the wires would disconnect easily, causing our circuit to be open and incomplete. This hindered our progress a lot, as we had to constantly go back and reconnect the wires, causing us to waste a lot of time. Our solution was to keep the wires connected together as a bunch, instead of pulling them apart and separating them. This helped to prevent the wires from becoming undone.

Lastly, during the assembly process, we realized that the glue we were initially planning to use for connecting the parts together would not work for acrylic pieces. After consulting the Technical Executives at W319, we used a different type of glue, an acrylic glue that was more suitable for gluing different pieces of acrylic together. However, this also led to another minor problem, as the glue applied was not sufficient, causing our tea maker to fall apart easily. This was resolved by returning to W319 to reglue the structure. The parts held on together more tightly after regluing, especially because we had applied more glue in the second round to reinforce the adhesion.

Other Limitations and Shortcomings

It was difficult for me to place the wired electrical components into the electronics compartment all at once. This was because all the walls of the electronics compartment were glued together at a slight angle, thus putting in the breadboard and Arduino Maker-Uno board directly inside with the wiring connected was difficult.

• Workaround: I disconnected all the wires first, placed the breadboard and Arduino Maker-Uno board inside by tilting it at an angle, then reconnected all the wires to the electrical components.
• Possible Improvement: We could design the tea maker to be longer in terms of its breadth. This would make placing the electrical components wired to the breadboard and Arduino Maker-Uno board easier.

The stirrer length was too short, thus when the cup was fully filled with water, it was only partially submerged under the water. The partially submerged stirrer would not be able to mix the water and tea easily.

• Workaround: I placed a small piece of acrylic under the cup, so that the cup would be more elevated, and the stirrer would be able to be fully submerged under the water.
• Possible Improvement: The stirrer length can be increased. Alternatively, we can increase the height of the cup so that it can be filled with more water.

There was no space for us to install the LCD Display at the front of the tea maker. Without a place to put the LCD Display, our LCD Display would dangle away at the side, and potentially be disconnected due to its weight dragging the connecting wires apart.

• Workaround: I balanced the LCD Display on top of the tea maker wall. This ensured that our wiring would not get disconnected, and our LCD Display would function as per normal.
• Possible Improvement: We can design a separate piece to be laser cut for the LCD Display to rest on. This piece will act as a platform for the LCD Display.

Lastly, there was no space in the back for the Arduino cable to fit through to connect to the power source. Without a power source, our tea maker was unable to function.

• Workaround: I removed the cover piece so that the Arduino cable would be able to connect to the power source.
• Possible Improvement: We can design a small slot on the back plate for the cable to pass through, so that it can connect to a power source without having to remove the cover piece.

Lastly, some other potential improvements that we can make are including a speaker for the buzzer, so that the alarm sounds emitted by the buzzer to notify the tea’s completion can be amplified to reach its user who may be in another room. We can also code the buzzer to emit different tunes at different timings, as the code used currently contains only one sound file. This means that even though the Arduino board was programmed to buzz at different timings, the buzzer would still emit the same soundtrack at each timing, thus there is no way for the user to know if their tea has actually finished brewing, or is just past a certain timing.

5. Project Design Files as Downloadable Files

The link to download the files can be found here:

https://drive.google.com/drive/folders/1Hpg3Z0ATptPvXfuOlwKZuCQXjBYVSNz2?usp=sharing

Personal Reflection

This project of ours was very meaningful and very fulfilling. It allowed me to practice and apply the various skills I had learned in this module, Chemical Product Design and Development, as well as its predecessor in the previous semester, Introduction to Chemical Product Design. The various skills learned from the previous semester were Computer-Aided Design (CAD), Sketching and Design Specification. The skills learned from this semester were Laser Cutting, Applications & Implications, Parts-Whole Analysis, Arduino Programming, TRIZ and 3D Printing. It is unfortunate that some of the other skills learned this semester, such as Design of Experiment (DOE) and Hypothesis Testing, could not be implemented while we were carrying out this project. Nevertheless, I am sure I will be able to apply all of these skills in the upcoming Capstone Project.

At first, I thought that this project would be very time consuming and extremely complex, as we had never designed an actual working machine before. However, after going through the tutorial lessons, we gained more relevant knowledge, and these relevant knowledge was applied throughtout the entire project to help us complete it.

As a group, we all managed to improve and grow together. We know better understand the importance of teamwork, and are able to better allocate tasks to each group member based on that individual's strengths. This greatly improved our efficiency and productivity. Another important lesson learned was that failuer will always be a part of our learning process. We can never expect when our plans will be derailed by something that was not anticipated. A prime example was when our LCD Display suddenly stopped working even though it was working fine the week before. This led to a lot of frustration as we could not find the source of the issue, even though we had already checked all the wires to be working and checked that every wire was connected to the right port. From this, we learned that improvisation and adaptability is an indispensable skill to possess, as it can help us respond to curveballs and return to our original plans without any major issues arising. All in all, this journey to make our tea maker was an insightful and thrilling one.