Progression of the Sensor project

Alright as promised from my last post here is a progression of the circuit built in the use of our sensor project.

1. So first we had to come up with a circuit that did exactly what we wanted it to do. This was done in a more or less trial and error fashion.
After we came up with the right circuit this is what the circuit on the bread board look like:

Incredibly messy, right?

2. Once we got the circuit right. We made it neater and mounted it on a plastic board along with an arduino.

Looks much nicer!

3. We realized shortly there after that we could only use 2 op amps (those little black squares) instead of 3. (Look at the picture above and below. You'll see there are 3 in the picture above and only 2 in the picture below.) We altered the circuit, constructed a new, and mounted it on a metal board, along with the arduino, and the power source (a 9V battery).

Now our power supply (9V battery) is present. (Top left).
My hand for size reference. Still way to big! 

4. The next step was to essentially transfer the circuit onto a a printable circuit board (PCB). This was done using a technique known as soldering. A process in which any of various alloys fused and applied to the joint between metalobjects to unite them without heating the objects to the melting point (Dictionary.com).

This is the PCB. All the components are there but
pretty much all the circuitry is underneath the
board. 

It's the perfect size, as it's the same size as the arduino.
The identical size allows us to just stacked them
on top of each other along with the battery.
 All the components will be wired together correctly
and placed in a box just barely larger than the PCB/Arduino.

5. Next step is to stack the PCB on top of the arduino stick it in a box the size of a fist, hook the arduino, PCB, memory chip, and screen to each other. And we'll have a final project. 

The middle of the sensor is made of porcelain.
The structure is such that when pressure is applied
electrons move around and that movement of electrons
forms a signal which can be detected in the form of
current. 

 *The final project will be a little box with a screen on it and the piezo (aka the breath sensor, seen below) coming out of it. You will be able to stick the sensor under a anesthetized rat or mouse and be able to read the breath rate off of the screen.  
It's essentially a portable breath rate monitor.  

THIS IS SOOOO COOL. At least I think so.

Weeks 6 and 7

Hello Again!

Last week, I primarily focused on the electrode project.

Last Monday and Tuesday, I prepared to platinum samples and on Wednesday I took them to the Electron Microscope.

The platinum wires that I am using are incredibly small (.00508 mm on diameter). In addition platinum is extremely expensive. Therefore to coat them effectively I soldered the mini platinum pieces to larger copper wire pieces (see picture below). Then I coated just the very tip of the wire. The platinum was only approx. 1cm long, but the coated part was only 1-2 mm in length.

Right one got coated. Left one didn't.
You can actually see a visible difference:
on the right, the tip of the platinum (small silver wire)
is black.

On Wednesday I took the coated wires to the Electron Microscope, where I actually got to learn how to run the election microscope by myself, which I was very lucky to learn. After learning for about 2 hours I ran some scans myself.

The results?

Not great. :( Only 1 of the 2 electrodes ended up being coated. I don't know why, and I would have to go back and figure out what happened, but as the SRP is coming to a close I don't know if I'll have enough time. Even if I don't get to finish this project from beginning to end, I learned so much about neurochemistry so it wasn't in vain.

This week though I have only been working on the sensor project. The screen and memory chip that we are going to integrate have finally come in in the mail, and I will be working with the grad student to integrate the this week and next week.

In addition, Monday and Tuesday I transferred the circuit we built on a bread board to a small plate. This new plate is also the size of an arduino so it'll fit right on top and fit perfectly in a little box.

This project is so amazing and I am truly enjoying. I'll post some pictures of it's progression later today.