Presentation Time!

Figure 1: Graph showing voltage over time

We had our presentation in Engineering on Tuesday! We didn't win the nomination for our team section, but we're still going to continue as hard as we can with our project. Our idea still is a very viable one and could help a lot of people if put in the right direction. Before the presentation, we did one last check to make sure we were storing energy, and we were! The Matlab plot showed that after it was charged up, it had a constant 5 volts that would allow it to charge a battery.

Week 7: Electrical Components complete

Completed Piezo circuit

The final product of our electrical design is complete. After numerous circuit diagrams and multiple bread board designs the most voltage efficient circuit was created. The final circuit board actually runs similar to a breadboard design, with a copper wire running through one entire end of the board. While creating the circuit, we made a mistake in attaching the first copper wire, as it turned out to be from some sort of resistor component. We also 3D printed another piezoaqueduct for our final mechanical design. Along with this, we learned to utilized an arduino to collect real-time voltage data to display data.

Piezo crystals hooked up to arduino

Week 6, 3D Print

Image 1: 3D printed piece

Image 2: Intended function; blue:force; orange:tool; green:piezocrystal

3D PRINT SUCCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
The purpose of this piece is to direct the input force onto the piezo crystals. Since the crystals actually produce voltage from distortion and shearing, a sharper directed force produces better electricity. The modeled aqueduct-like structure, dubbed the "piezoaquaduct", focuses the relatively spread out pressure onto specific points in the crystals. This simple mechanical feature should greatly increase the yield of the piezoelectric generator.

Week 6, Engineers make a Quantum Jump

a circuit diagram showing the various component
used to charge the battery

After several weeks of research and experimentation, we finally set up the right circuit diagram which was able to increase the voltage of a 1.5 volt rechargeable battery from about 0.03Volt to 0.04volt during our first test. this value showed a general increase with further testing. although this voltage increase is not that huge of a value, we used only one piezo to perform this experiment and also our circuit lacked a DC-DC converter which is basically to be used as a tool for ensuring that the charge in the capacitor is efficiently and effectively transferred to the rechargeable battery and hence reduce power loses or voltage leaks.

Week 5, The fails and wins

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A picture of Shaumik trying to 3D print the aqueduct-like structure

We decided to go to the innovation studio to perform some tasks on the project. the first thing we did was to use the soldering iron to solder all the defective piezo and then tested them all out to make sure they were working. we then connected the set of piezo on a board to test whether series and parallel connections produced the most voltage since our previous test did not give any strong confirmation for either. after testing which connection works best, we then set up a circuit consisting of a 470 micro farad capacitor which was connected in series with a diode to ensure there is unidirectional flow of voltage and hence current. other component were also attached to it and through a continuous application of pressure to the piezo disc, we were able to charge the capacitor to about 1.9volts which was very constant until the capacitor was discharged. we attempted to 3D print an aqueduct-like structure to focus the pressure on the piezo crystals. this was however not successful as the 3D printer was malfunctioning

Week four, engineers do more

Figure 1. Daniel sharing his research with the group

Week 4, we were concentrating more on getting our specs right. Our timeline suggested that we had to begin with the electrical design, but we were still waiting more our piezo crystals order, that we got the night after lab. We then proceeded with finishing the Creo model of the shoe sole and we tried to mess around with the electrical devices we got from the lab. We started with a breadboard and connected diodes, resistors and capacitors trying to build a functional circuit, using a 9 V battery as the power source. While playing with the circuits, we did some research online about the optimal capacitance that we should be using for the circuit we were intending to build. We also got the chance to talk to Dr. Fred Allen to get an idea of how to control the amount of voltage going to the capacitor using a voltage regulator. After lab we headed to the Electrical Engineering department in Bossone to get the voltage regulator and a multi-meter to use when working at the dorm.

"Piezo board" and other shocking discoveries

Us measuring the voltage of the piezo board

Our previous tests so far have been on only a single piezo transducer. This week we devoted most of our time to learning the most effective ways to gain the most energy out of multiple piezo crystals. We first created a cardboard cut-out of a traced shoe, lovingly donated by one of our group members. However, we realized the best way to start would be using a square shape, like a breadboard for a proof of concept. Taking inspiration from numerous sources online, we found that the best way to arrange the piezo crystals was in series horizontally, with a parallel arrangement running vertically at the ends. It was also learned that having a stud, or any other hard, non-conductive object placed on top of the piezo would increase the electrical output via focusing the pressure to a smaller area. These two facts led us to our "piezo board," a proof of concept design that output a steady charge of 20 volts. Outside of lab, it was also learned that piezo crystals have the largest output, when attached to a foam, or any other easily compressible surface.