The project we have is a piezoelectric energy harvester.
Piezoelectric devices are those devices that can convert mechanical energy
into electrical energy. Because of this characteristic, these devices
have been used to harvest sources of energy such as
ambient vibration and convert this into energy generated to power small devices
Such devices are already commercially available, however those that are
in the market tend to function at a much narrower
frequency and at a lower efficiency than is useful for aerospace applications.
So what we've done in this project is design a device that allows us to
amplify the forces that are being put into the device so
that the energy that's harvested from it is also amplified.
We've done this and showed that we're able to be better
than commercial devices in the sense that we are
four times more efficient and 100 times
better in output of energy relative to force input.
So what we're gonna do here is demonstrate a comparison of the
performance of the device that we developed versus the commercially available device.
When this truck turns on, it's gonna vibrate
so that it provides the force input to the piezoelectric
device. And then, this device will then generate the voltage ??????
that's required to power the LED. And what we're gonna try to show here is
the efficiency of this system based on how quickly energy can be
generated to light up the LED. So, we can watch the timer and see how long
it takes for when the LED lights up.
(electric truck runs)
So what we're gonna show here now is using the same setup as the one we used for the
commercial device. So, we're using the truck, which is vibrating at 23 hertz.
That's the optimum frequency for the operation of the commercial device.
It's not the optimum frequency for our device, so we have a weight added on to our
device because ours operates at a much higher frequency.
Ok, so... it was done in two seconds!
Alright, what we're demonstrate now is
the performance of the devices at their resonant frequency. And the resonant
frequency is the optimum frequency at which they can operate. So we're gonna
generate vibration using this device and to compare the performance
of our device versus a state of the art commercial device
What we're gonna do is run a test for the same amount of time. So the timer will run to ten
seconds and what you want to be watching is the voltage output.
The voltage output of our device should be much greater than the commercial device.
And that is proportional to power because power is proportional to
voltage squared. (beep)
(beep)
(commercial device registers 1,785 volts)
(beep)
(buzz)
(beep) (IPP developed device registers 7.035 volts)
So another facet of this device is we did not
require very high vibration frequencies in order to generate voltage
As you can see, we're using finger pulsing to generate voltage
It's enough voltage to power small devices from motions that
come, say, from walking by humans.
(IPP developed device registers 1.671 volts)