Blogpost #4: Reflect and Share

Final Product: Flashlight powered by our hand









Thermoelectric generator -Handle


An aisle for cold air
Rechargeable battery powered by a thermal and piezo generator




How it works

: The main idea here is the concept of the thermoelectric generator and piezoelectric generator. The thermoelectric generator produces the energy by the difference of temperature. If one side is heated and another side is cooled, it generates the energy. That’s why I made a flashlight design with an empty aisle inside a pipe: the cold air comes inside the pipe and cools the cooper attached at one side of the thermoelectric generator, which increases the temperature difference between the side cooled by cold air and another side cooled by thermal of hand. This phenomenon is called the Seebeck Effect. Also, the piezoelectric disc generates the energy as it gets the pressure. Therefore, whenever a user presses the piezo button, the energy is produced. By adding the spring and foam as a soft button on the piezoelectric disc, I enable the user to press the button comfortably with less force than they press only the piezoelectric disc. 

These two types of energy generators are a typical example of nanogenerator.


Explanation of my Design

  1. Piezoelectric disc button
Pressing the Piezo disc
Piezo disc with spring and foam attached


piezoelectric disc

Explanation: As a picture, two buttons are attached to the flashlight. Most users might don’t know those buttons have a special power and actually generate the energy. Throughout many testings, I realized that the piezo disc itself is difficult to be pressed. Also, I was not sure if I really press the right position to generate the energy or not without the  Digital Multimeter. However, by adding the spring and the foam on the piezoelectric disc, I could notice whether I press it or not. In addition, it feels more soft and comfortable to press the button than the piezoelectric disc itself.


2.  Thermoelectric generator

An Ailse for cold air


How does a thermoelectric generator work

Explanation: Since the thermoelectric Peltier generates with the temperature difference, the more temperature differs, the more energy is produced. By leaving the empty hole inside the flashlight, I let the cold air to go inside and cool the one side of thermoelectric Peltier. As another side is heated by humans’ hand, the energy is generated.


Explain the areas you were successful in the product/process

  • Design: My sketch and design were easy and detailed so that my friends could understand only by looking at my sketch.
  • Creativity: I tried to use the idea outside of the box, not the original with tutorials. Therefore, my project is fully processed without any video tutorials. From design to build, 80% of the process is done by me. In fact, I was inspired by the idea of a flashlight powered by the thermal energy of humans’ hand, I did not follow that process. I added my ideas such as adding the piezoelectric disc to generate more energy, using a rechargeable battery instead of a voltage booster.
  • Effort: Even though I failed on the first design, I didn’t give up, and succeed on the second design. I stayed until 6 P.M on Thursday and tired my best to finish.

Explain the areas you need to improve in the product/process

  • Planning: I think my planning was weak. If I planned more carefully, I would not fail even on the first design. However, since these two ideas are created by me and there is no tutorial, I wasn’t sure my project would work or not. After all, I started this project as a challenge, unlike other people who just follow the tutorial.
  • Electrical circuit: I had no knowledge about how to make a circuit that transfers the electricity. I didn’t know much about electrical engineering. I will make sure that I know everything about my project before I start in next time.


Explain the impact of this project on the environment and potential client/consumer.

Miner: since miner works at a dark and cold place, they are the perfect audience for this flashlight. Moreover, although they are in dangerous situation, they no longer need to worry about the energy for light.

Adventurer: they can use this flashlight effectively since they are usually in a dangerous situation. Even though they are in a dangerous situation without a battery, they can use a flashlight.

A country where the energy is insufficient: citizen does not need to worry about money for the light. They can use this flashlight to study at night, work in a dark place, and any other action that the light is necessary.


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