The document describes a robotic arm activity where visitors build and operate robotic arms using pneumatics or hydraulics. Participants will use materials like wooden blocks, dowels, syringes and tubing to construct arms that can lift and move styrofoam balls. The activity can be a short, structured demonstration or a longer workshop where participants problem-solve design challenges. Safety notes include supervision and avoiding small parts as choking hazards.

1. Hydraulic/Pneumatic Robot Arm
Visitors will build and operate robotic arms using pneumatics or
hydraulics. This can be done as a short structured activity, or as a
more challenging workshop.
• Pneumatics
• Hydraulics
• Design
• Engineering
• Robotics
• Force
• Pressure
Related exhibits: Give It A Lift, Earthmovers, Air Tubes
Floor Program version
Time: 5-10 minutes
Ages: 8 and up (Grades 3 – 12)
Staff : Supervision required, at least 1 teen/volunteer.
Safety issues/special notes: Visitors may try and move the arm to “throw” the ball. Do not
use balls that could be classified as choking hazards. Water-filled tubes can leak. If pins or
finishing nails are used, staff supervision should be vigilant to avoid visitors causing a puncture
wound due to improper use.
Materials:
• Per Robot (enough for 10 robots provided):
o 20 cm x 20 cm (8” x 8”) base wooden base
o 25 cm (10”) long block with groove at one end (part A)
o 20 cm (8”) long block with tongue joints at both ends (part B)
o 20 cm (8”) long block with a groove at one end (part C)
o 2 pieces of 3 mm (1/8”) diameter dowel
o 1 piece of 6 mm (¼”) diameter dowel
o 1 cardboard box
o 6 plastic syringes (20 mL)
o Three 30.5 cm (1’) lengths of tubing
o Short pin or finishing nail (optional)
• Empty coffee can without lid
• Styrofoam balls
• Duct Tape
• String
continued…

2. Robotic Arm continued…
Preparation:
NOTE: The robots do not all have to look the same, but they will all need to rotate and have at
least one rise/fall elbow. Here are instructions for the standard build (see attached Diagram):
1. Put 6 mm dowel in hole of wooden base so that the bottom of the dowel is close to the
bottom of the base.
2. Insert exposed end of 6 mm dowel into hole on bottom of part A.
3. Put tongued end of part B into groove of part A, and lock into place with 3 mm dowel
4. Put other tongued end of part Bk into grooved end of part C, and secure with remaining
3 mm dowel
5a. Hydraulics: Fill one syringe with water. Attach 30.5 cm long tubing to syringe. Squeeze
syringe until water starts to drip from tubing. Put tubing in water and fill syringe and
tubing completely with water. Attach empty (plunger all the way in) syringe to other end
of tubing. Any air bubbles in the tubing or syringe will restrict the desired motion
(compressible fluid).
5b. Pneumatics: Attach 30.5 cm long tubing to a syringe with the plunger pressed all the
way in. Attach the other end of tubing to a syringe with plunger pulled all the way out.
6. Repeat step 5a or 5b with two more syringe pairs.
7. Tape one syringe to part B so that the closed plunger is at the B/C joint and against the
bent part C (see figure)
8. Tape a second syringe to part A so that the closed plunger is at the A/B joint and
against the bent part B (see figure)
9. Screw eyehook into end of bicep, near shoulder.
10. Tape 3rd syringe to base and secure a small piece of string to closed plunger with other
end tied to eyehook. Have plunger as close to eyehook as possible.
11. Use tape or finishing nails at end of hand for lifting (insert nails into hole at center of 8”
long “hand”.
The hardest part is usually filling the syringes properly and figuring out how to do the shoulder
rotation (pivoting around the base).
Procedure:
1. Challenge visitors to use the robot to place the Styrofoam balls into the coffee can.
Extended Workshop version
Time: 25+ minutes (depending on challenge provided and level of preparation)
Ages: 11 and up (Grades 5 – 12)
Staff : Supervision required, at least 1 teen/volunteer/staff per 10 children.
Additional safety issues/special notes: Students will require assistance screwing eye-hook
into base. Instruct students to be extra careful with sharp objects like tacks pf screw points.
continued…

3. Robotic Arm continued…
Additional Materials (optional):
• Tubing (limit to two additional 30.5 cm lengths per group)
• 10 mL syringes (limit to 2 additional per group)
• Scissors
• eye hooks
• thumbtacks
• nails (or tacks)
Preparation:
1. Have robot parts put together as individual kits.
2. Additional materials should be laid out on a table or community work surface.
Procedure:
1. Begin by brainstorming about robotics, using some of the “Questions to Think About”.
2. Present a challenge of building a robot that can move the Styrofoam balls from one can
to another. They can use the materials provided in their kit, plus the additional materials
laid out.
3. Have students work in groups of 3-4
4. Optional – Have a competition to see which team can transfer the most balls in a set
amount of time.
Questions to Think About:
What are some of the different jobs a robot might do.
Are all robots the same? How do they differ?
How do robots move? Do all robots move the same?
What methods made the robots move the fastest?
What things made the robots move with the most accuracy or the most precision?
If you could ask for 2 additional parts, what would they be, and why?
Science Content:
There are many types of robots. Some do more detailed work, like microsurgery that requires
exact precision. Some do heavy lifting, like arms tat lift cars. Some need to move things fast
and some need to move things slowly and carefully. Machines that require movements in
short, very fast, bursts often use air pressure, called pneumatics. Moving very heavy loads
often requires a more dense fluid than air, so they use a liquid. We call this hydraulics. There
are 6 typical robot motions – rotate, rise, fall, twist, open, and close. Some important parts &
functions of a robot are: the end actuator, elbow, base, and shoulder (see diagram).
Related activities:
• Giant Lever Demonstration
• Liquid lift – “The Science Factory” by Jon Richards, Cooper Beech Books, page 40.
continued…

4. Robotic Arm continued …
Diagram: