By Barb Sauer
Light Up the Fox will celebrate our river history on Water Street in Appleton (Dec 20 – Feb 11) with a LED light display designed by tech ed students from Appleton East and West. Hydroelectric power, using the Thomas Edison system, is a key historic milestone that the student displays will portray. Hydroelectric power came to our community in 1882; Appleton was a very early adopter, among the first in the world.
The students are creating a link to their community’s history for everyone to enjoy. In addition, there are links between this history and the student’s educational interests. Light up the Fox takes pride in the STEM––science, technology, engineering, and math––learning opportunity within this student project and the partnership with Fox Valley Technical College. We would like to point out some of these links.
What phrase first comes to mind when you hear “Silicon Valley?”
Bill Gates? Apple Computers? Facebook? IPO (if you’ve made a fortune in stocks)? Or breast implants (if you’re mind quickly wanders off-task)?
Would any of these words surface: Periodic Table (if you’re science savvy)? Semi-conductor (if you’re quite STEM-literate)? And moving farther down the science scale: Transistor? P-n junctions? And even farther towards “geekville,” “maker heaven” and “Arduino boards?”
Some of these words may be foreign to you, but they are well known in today’s high school technology education classes and the field of electronics. Imagine the days of yesteryear, when the world of light bulbs and electricity seemed just as foreign to the general public.
I’ll try to shed some light (pun intended) on the connection (puns galore) between this old world of invention which included the likes of Thomas Edison (1847-1931) and the new world of hi- tech innovation which includes maker groups and open source hardware/software.
The tutorial starts with the old-school task to illuminate a light bulb given a battery having positive and negative terminals and wires. This shows the science concept of electrons moving in a closed circuit through a conductor to produce light energy. The next step is showing how magnetic and electric fields interact. Often this is done by repeating the Oersted discovery, showing how a current in a wire can move a compass needle. This becomes the basis of electromagnets, important components of industrial machines and generators.
Materials, like metals, are used in these experiments because they are conductors, electrons move through them. However, as early as 1833 Michael Faraday (1791-1867), a scientist who made great contributions in this area, found some materials exhibit conductive properties only under certain conditions (in this case, silver sulfide crystals at high temperature); these materials are called semi-conductors. Electron mobility in a gaseous state was deployed in inventions such as the cathode ray tube (1897), which was the technology behind early TV’s (1934). However, in time, this gas-state technology was replaced by a solid-state option.
The first well-known application of solid-state semi-conductor materials was the transistor radio of the early-mid 1900’s. The designs started with special crystals and minerals that were discovered to have the unique property of a semi-conductor.
During this time, the understanding of electron mobility in a semi-conductor grew. Transistors evolved to have a silicon material with p-n junctures (p for positive and n for negative). From a material standpoint, “p” can be thought of as holes and “n” as excess electrons. Having both p and n, makes it a “diode” (di = two and ode for electrode). An example of an electrode would be the terminals of a battery–– cathode and anode––each separately having a different charge. A diode combines the two charged zones in one material.
Near the turn of the 20th century, material scientists had a heyday, improving semi-conductor properties by doping to create zones of holes and electrons. In 1956 silicon semi-conductors came to Silicon Valley, with the Shockley semi-conductor laboratory in Northern California. William Shockley, from Bell Labs, won the Nobel Prize in physics (1956) for his discoveries.
The applications broaden when semiconductors are used in an Integrated Circuit (IC, aka microchip or “chip”). Today such chips can have several billion transistors. As this technology evolved, the electronics field blossomed.
Now we get to the biggest geek word in our list, the Arduino board. This is a single-board micro-controller used to build interactive objects or environments. The Arduino, an integrated circuit, works with a sensor and an actuator (motor) to read inputs and respond with action. It’s the basis of robotics, thermostats, and motion detectors. It’s a popular tool for technology hobbyists and maker groups (somewhat like networks of modern day “tinkerers”).
Many popular light displays synchronized to music use such micro-controllers. These can be purchased along with programs from companies such as Light-o-rama. Otherwise, the light displays can be made with an Arduino board, bought as a do-it-yourself (DIY) kit to be assembled and programmed with open-source hardware and software. Last year’s design teams used such kits to build micro-controller boards. It’s our vision to grow the program and the technology to include more DIY features that enhance the light displays by animating them, making them interactive using sensors and actuators, or synchronizing them to music.
The effort and the Light Up the Fox non-profit organization is new and starting small, but the visions are big. More volunteers are always needed. If interested, contact us through lightupthefox.org