How to Build a Syringe Robot

By Laurel Brown

Robots are machines you can program to perform any task, particularly tasks that are dangerous or far away. While most industrial robots work primarily by using electrical power and computer programming, some aspects of robotics work with hydraulics. Hydraulics uses pressurized liquids to cause motion, and a syringe robot uses the liquid in syringes to move the robot’s parts. You cannot program a syringe robot as you would an industrial robot, but you can make a syringe robot arm to move objects from a distance.

Steps to Build a Syringe Robot

Build the parts of your robot arm using wood or cardboard. You need a base on which to rest the structure, a tower coming up from the base, an arm extending horizontally from the tower and two small, flat pieces of wood or cardboard for the gripper. Attach the base, tower and arm with nails or wood glue.

Attach a large syringe to the tower using duct tape. The plunger should be toward the top of the arm. Use duct tape to affix the plunger to the underside of the arm.

Attach a smaller syringe to the arm with duct tape, with the plunger facing toward the arm end that will attach to the gripper.

Attach the gripper pieces to the hinge with screws. The hinge then attaches to the end of the smaller syringe, wired so that the hinge opens and closes as the syringe plunger moves in and out.

Connect the syringes to rubber tubing, reinforcing the connections with duct tape as necessary.

Connect the rubber tubing to two control syringes (one for each of the robot’s syringes). Fill with water the syringes connected to the rubber tubing.

Depress the control syringes to increase the pressure inside the robot syringes. This will extend the plungers and move the robot parts. Pull back on the control syringes to cause motion in the opposite direction.


Test your assembly before adding water by manually moving the syringe plungers in and out. If your robot moves correctly when the syringes move, your design is good. If you want your robot to look nicer, substitute metal braces, screws and nails for the duct tape. A 5-cc syringe is good for the smaller syringe, while 20-cc syringes work for the large syringes.


Remove all needle tips from syringes before you begin. The rubber tubing fits over the needle end of the syringe, and you do not want anything sharp there. Make sure your syringes and tubing are well-sealed to keep sufficient pressure for movement.

About the Author

Laurel Brown has several years experience as an educator and a writer. She won the 2008 Reingold Prize for writing in the history of science. Brown has a Ph.D. and Master of Arts in the history of science and Middle Eastern studies from Columbia University, as well as a Bachelor of Arts in astrophysics from Colgate University.