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.