Embedded Files
STEM Principles to Consider/Research
STEM Principles to Consider/Research
STEM Principles
STEM Principles
STEM Principle 1: Heat Transfer
STEM Principle 1: Heat Transfer
The connection to the project problem: Heat transfer is an essential part of our design, as the product relies on heat production from the human body during exercise to do its job. Transferring this heat as efficiently as possible to our device for further conversion is important for a worthwhile product and one that consumers will want.
The connection to the project problem: Heat transfer is an essential part of our design, as the product relies on heat production from the human body during exercise to do its job. Transferring this heat as efficiently as possible to our device for further conversion is important for a worthwhile product and one that consumers will want.
Q=mcΔT
In testing, we are creating this heat transfer by applying a significant cold on one side of the TEG module and a significant heat on the other side. Thus, the heat should transfer from the side with greater thermal energy (hot) through the TEG and to the side with less thermal energy (cold). This heat transfer creates a movement of energy within the TEG that we can then utilize.
In testing, we are creating this heat transfer by applying a significant cold on one side of the TEG module and a significant heat on the other side. Thus, the heat should transfer from the side with greater thermal energy (hot) through the TEG and to the side with less thermal energy (cold). This heat transfer creates a movement of energy within the TEG that we can then utilize.
STEM Principle 2: Energy Conversion
STEM Principle 2: Energy Conversion
The connection to the project problem: The conversion of energy from one form to another is the key component of what makes our design unique. We begin with thermal energy that is expended from the body during exercise through the difference in heat with the environment. The energy is then converted to electrical energy which can be used as a final output to power a charging device. This solves the problem of the device using up electrical energy with no sustenance during usage. In an ideal world, electric energy output is equal to thermal energy input because of the law of conservation of energy.
The connection to the project problem: The conversion of energy from one form to another is the key component of what makes our design unique. We begin with thermal energy that is expended from the body during exercise through the difference in heat with the environment. The energy is then converted to electrical energy which can be used as a final output to power a charging device. This solves the problem of the device using up electrical energy with no sustenance during usage. In an ideal world, electric energy output is equal to thermal energy input because of the law of conservation of energy.
In testing, the energy conversion is happening within the TEG and being measured as electrical output. We are creating thermal energy that is absorbed and measuring the electrical energy output that the energy is converted into.
In testing, the energy conversion is happening within the TEG and being measured as electrical output. We are creating thermal energy that is absorbed and measuring the electrical energy output that the energy is converted into.
STEM Principle 3: Electricity/Electric Current
STEM Principle 3: Electricity/Electric Current
The connection to the project problem: The TEG module, which is the main component of our product, charges devices by creating a current. This current is an essential part of the process by which our project charges devices. The actual charger component of the product takes a current from the generator into the cable where it can be applied to any device to be charged. Electrical energy = P*t and Power = I²R. Also, I=V/R according to Ohm's law. For testing, we are measuring the current and voltage that travel through the usb port and out of the TEG module to ensure it flows in practice as it should be.
The connection to the project problem: The TEG module, which is the main component of our product, charges devices by creating a current. This current is an essential part of the process by which our project charges devices. The actual charger component of the product takes a current from the generator into the cable where it can be applied to any device to be charged. Electrical energy = P*t and Power = I²R. Also, I=V/R according to Ohm's law. For testing, we are measuring the current and voltage that travel through the usb port and out of the TEG module to ensure it flows in practice as it should be.
Testing Criteria
Testing Criteria
Testing Procedures
Testing Procedures
TEG:
Initial Conditions:
Checking that TEGs are not physically damaged
Providing a hot temperature source and cold temperature source to the unit (TEGs)
Prepare the sources used for the TEGs - put the heat pack on high and ice pack in the freezer for several hours until fully frozen
Both sources being able to be last for 10 minutes (time of test) (still have a significant temperature difference of at least 20℃ {rounded to nearest degree})
Procedure:
Step 1: Put the heat source on the bottom side of the TEG (TEG resting on top) and put the cold source on the top side of the TEG at the same time, so that it can take the input of the temperature difference.
Step 3: Leave the heat sources in contact with the TEG for 10 minutes
Step 2: Connect the multimeter (as shown in image to the right) and connect the wires of the TEG to the leads corresponding to positive (red) and negative (black) and after 10 minutes measure the generated current that the TEG gives.
Frame:
Initial Conditions:
Apparatus must be attached to the arm of a team member, wrapping both straps around the arms, securing the velcro, and including all of the parts of the final prototype, including the 2 TEG modules and USB breakout board.
Procedure:
Set a 15 minutes timer using the iPhone timer app.
Walk to the field
Run one lap around the track
Walk back to class
After the timer finishes, assess the comfortability, durability and security by the standards above.
USB:
Initial Conditions:
Get breadboard and connect wiring from a 5V power supply. Connect output of battery to input of breakout board. Connect output of breakout board to the input of the USB port piece and then plug in the charging cable to the USB port and plug it into a testing device (phone)
Procedure:
Turn on 5v power supply
Connect output directly to USB circuit board (as shown in image below)
Check iPhone to see if charging icon is present and USB port is properly transferring current
Surface Area:
Initial Conditions:
3D printed block same size as TEG attached to armband frame
Paint or other material that can create mark applied to bottom of mock TEG
Armband attached to team members arm as securely/tightly as possible.
Procedure:
Have test subject user attach armband frame to forearm as securely as possible with full contact made (strap is fully tight)
Leave device attached long enough (Approximately 1 minute but periodically check to see if mark is made distinctly) for paint to make a distinct marking on the arm and press down firmly to create a more distinct mark.
Take armband frame off and measure the area of the paint on the users arm
Repeat procedure with all different parts of arm (upper bicep, lower bicep, upper forearm, lower forearm) and measure the percent contact area for each one.
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