Typically the bots and projects we see are constructed from off-the-shelf components: stacks of development boards, servos, solenoids, and sensors. Sean Hodgins takes a few moments to show a great example on how to make your own actuators so that they work similarly to a solenoid.
As Sean points out, this is somewhat common practice in radio controlled avionics, because many off-the-shelf parts are simply too heavy. His example actuator uses a 3D printed body and might be the perfect size for something that needs to tap a surface or pluck a string. In the video, Sean goes beyond just showing how to assemble his and explains why and how it works, encouraging you to design your own.
Sean has been doing fantastic lately with videos that always seem to teach something very clearly. You should go check out his channel.