activity page will offer:
in Functional Electric Stimulation
opportunity to integrate physical science (circuit construction)
with life science (coordination and technology application)
hands-on experience in defining coordination
- bell wire
- 2 button switches*
- two iron nails
- 2 "D" Batteries
- steel bearing (1/4" or larger)
- cardboard or scrap foam core
type of pressure switch or doorbell button will do.
Review all safety procedures associated with heat generated
by this type of electromagnetic circuit. Remind students to
keep the circuit closed for ONLY short periods of time. With
the current flowing, the wire will heat to temperatures that
can cause burns.
1 - Building the Coordinated Clip Fall
- Work in teams of two. Examine both the schematic drawing
and the set-up illustration.
- Gather the materials needed to assemble the two electromagnetic
circuits and the support board.
- With your instructor's approval and guidance, assemble
the wiring and platform. Wrapping insulated bell wire around
an iron nail forms each of the two electromagnets. Each
nail should have 15 wire wrappings.
- Position the magnets as shown in the illustration. Use
tape to secure the magnets to a base made of either foam
core or packing cardboard. Remember that the magnets need
to be placed so that they can direct the falling ball into
the target zone.
- Slightly prop up the release edge of the ramp. Only a
small rise is needed to insure a slow-moving ball. If the
angle is too steep, the ball may roll too fast to be affected
by the electromagnets.
- Place a steel ball in the release location as indicated
in the diagram.
the ball and observe its slow roll down the incline. Turn
on the upper electromagnet. The ball's path will be diverted
towards the magnet. HINT: Here's where you'll need to fine
tune your setup. The critical balance between the magnetic
attraction and ball's roll depends upon several things such
as the battery strength and mass of the steel ball. You'll
have to reposition the magnets until the ball follows a
path that is influenced by the attractive force of both
the ball rolls past the first magnet, switch on the lower
circuit. The ball should be further diverted as it is attracted
to this second magnet.
the release and the coordinated switching between circuits.
Your goal is to have the ball roll into the target area.
practice, practice. How far you can divert the ball's downward
roll? Have you developed any tricks or techniques to improve
What caused the ball to move down the ramp?
force diverted the ball's downward roll?
produced the magnetic force?
no magnetic attraction affected the ball's movement. Describe
How can this laboratory experience be applied to the challenges
faced by FES?
the simplest actions require an incredible amount of coordination.
To explore this concept, identify a class leader. The leader
stands in front of the class. Each student unlaces a shoe
or sneaker. The leader must then instruct the class on how
to tie a shoelace. The instructions can only be given orally.
The leader is not allowed to physically assist anyone or demonstrate
an action. The students are limited to only voice commands
and must follow these commands as best they can. After this
experience, discuss the elements of a coordinated sequential
movement. Compare and contrast this experience with a "standing
transfer" movement? How is it similar? How is it different?
IN YOUR WORLD
Have you ever examined an electric toothbrush? If so, you
know that this device has its built-in battery located in
the brush handle. Although the stand has an electrical connection
to the wall outlet, the handle isn't wired to an electricity
carrying wire. Its batteries charge through induction. Electricity
that pulses through the stand produces an electromagnetic
field. This field induces a current in a coil located in the
toothbrush handle. This current charges the batteries in the
toothbrush. Think about it. What is the advantage of this
type of charging?
Why is this type of charging utilized for meeting the electrical
demands of biotech devices implanted beneath the skin?
Cleveland FES site
An overview of the current clinical applications of FES
The FES Society Homepage
activities in this guide were contributed by Michael DiSpezio,
a Massachusetts-based science writer and author of "Critical
Thinking Puzzles" and "Awesome Experiments in Light & Sound"
(Sterling Publishing Co., NY).
Academic Advisors for this Guide:
Corrine Lowen, Science Department, Wayland Public Schools,
Suzanne Panico, Science Department, Fenway High School, Boston,
Anne E. Jones, Science Department, Wayland Middle School,