Hydraulic Arm

Grades: 9th
Hydraulic Pressure, Engineering, Problem Solving
Key Outcomes:

In teams of two, students developed their design and engineering skills by building a hydraulic arm. Using only their keen observation, students recreated an exemplar hydraulic arm without formal instruction. Cardboard, medical syringes, plastic tubing, zip ties, and hot glue were made available to the students; however, specific values and amounts were left to them to decide.

Throughout the trimester, students managed materials, revised prototypes, and deepened their understanding of hydraulic principles and how they can be put to use moving objects. The goal was to build something a unique population could potentially use. One student applied these skills by designing and constructing not only an arm, but a hydraulic-operated hand.


For 9th graders Chanel and Kimberly, this project was a constructive problem-solving process.

“My first prototype didn’t work,” remembers Chanel. “Then, when Kimberly came in as a new student, we paired up. Eventually, after a lot of issues, we worked together to build a functioning hydraulic arm. It picks up an aluminum can, but it doesn’t move exactly how we wanted it to.”

There was a lot of frustration along the way, but Kimberly and Chanel persevered to push through each obstacle that arose. For example, their tubing wasn’t working well for their prototype, so they took a trip to Home Depot with their syringes to test different tubing types and get the correct type for their application.

“In the end it felt pretty cool when our arm picked up the can,” says Chanel. “It actually worked out, even though it felt like it never would.”

Video of a similar project
More on hydraulic actuators