DIY Storable Tubular Extendable Member (Tape Measure Style Extendable Robot Arm)

Hello,
I am on an FTC robotics team, and often robots are required to lift/reach objects. This year, a challenge was to reach up and grab onto a pullup bar; the robot then completed a pullup. One common method this year was to use a tape measure; the tape measure was unwound using a motor, remained rigid due to standout, and was then wound up, lifting the robot in the process.
I am now in the offseason and I want to improve on this design. I found that a very similar mechanism to the tape measure has been used for extendable antennas on spacecraft. I would like to create a similar mechanism. The main difference between the tape measure and the STEM mechanism is that the STEM extends a tube. The tube is rolled from a sprung piece of metal.
The piece that I am looking for is a material that could be flattened, but would spring back to its tubular shape like on the STEM. Does anyone know of any types of pipe or tubing that could be cut lengthwise and possess this springy characteristic? Is there anyway to create a material like this?
Thanks,
icecats