Ferrofluids
Energy Harvesting: Solar-Powered Cell Phone ChargerTry this!
(1-2 minutes)1. Choose a device from the choices listed on the
right.
2. Locate its source of energy (solar panel).
3. Cover the source with your finger. What happens?Whats going
on?
Solar cells or photovoltaic cells work by converting sunlight
into electricity directly using photovoltaics (PV). Its beginnings
can be traced back to 1876 when William Grylls Adams and his
student Richard Day discovered that selenium produced electricity
when it was exposed to light. A second source of solar energy
involves the indirect use of concentrated solar power (CSP). Solar
Powered Flower and CalculatorHow Solar Panels Work
Now try this! (5 minutes)1. Connect the fully-charger
solar-powered phone charger to your device (phone or tablet).2.
Observe what happens.
3. Describe the energy conversion process which occurs.
4. What are some drawbacks to using this device?Whats going
on?Generally speaking: The photovoltaic cells in the solar powered
phone charger collected sunlight directly, converted it to energy
and transferred that energy to the device. Specifically: A group of
photovoltaic cells are connected electrically and grouped together
in a solar panel. These photovoltaic cells are made of
semiconductors that absorb sunlight and release electrons to flow
freely. Photons of light jar electrons loose from the material
causing an imbalance between the positive protons and the negative
electrons resulting in an electrical field. The electrical fields
that surround photovoltaic cells are designed to cause electrons to
flow in a specific direction, creating an electrical current.
. Solar powered Cell Phone Chargerwith 2 devices charging.
Photovoltaic Cells
How is this ASSIST? Wearable Devices
The goal of ASSIST is to incorporate nanotechnology into
wearable self-powering devices that monitor and transmit data for
long-term trend analysis. Harnessing solar power to fuel the
operation of devices offers a promising means for achieving this
goal.
Learning Objectives 1. Participants will explain how solar
energy is converted into electrical energy2. Participants will
describe evaluate solar energy as renewable, clean
energy.Materials
Solar powered calculator Solar powered flower or other item
Solar powered phone charger Cellular phone or other device with
charger cord.Notes to the presenter
Before doing this activity, please do the following: Purchase or
locate the calculator and the solar powered flower before the day
of presentation. Charge the solar powered phone charger before the
presentation. Test the charger with the phone to make sure that it
will work.
Tips: 1. Make sure that your solar charger corresponds to your
phone; some models are phone-specific.2. Try out the demonstration
ahead of time to work out any bugs; allow time to call tech support
if there is a problem with the charger.
3. Since the flowers do not cost much ($1-3) have extras on hand
if one should get dropped or damaged and doesnt work.SAFETY:
Exercise any precautions when you are using electricity (phone
charger).Cleanup: None.Related educational resources
For further research: These are excellent articles on
nanotechnology, solar power and wearable devices.
1.
http://energy.gov/articles/top-6-things-you-didnt-know-about-solar-energy2.
http://energy.gov/eere/education/clean-energy-jobs-and-career-planning
3.
http://science.howstuffworks.com/environmental/green-tech/sustainable/5-solar-powered-gadgets.htm
4.
http://theinstitute.ieee.org/technology-focus/technology-topic/everyday-nanotechnology
5.
https://www.wearable-technologies.com/2014/07/energy-harvesting-for-wearables/6.
https://www.wearable-technologies.com/store/health.htmlCredits and
rights
Esta Lampkin, ASSIST Center at North Carolina State University.
http://science.howstuffworks.com/environmental/energy/solar-cell1.htm
HYPERLINK
"http://electronics.howstuffworks.com/gadgets/travel/solar-battery-chargers1.htm"
http://electronics.howstuffworks.com/gadgets/travel/solar-battery-chargers1.htm