You can design, print and etch your own PCBs from a flexible sheet of Kapton coated with a thin layer of copper. To do this yourself you need some special materials and equipment, and if you are not planning on etching circuits more regularly then it can be nice to start by looking for a local space that has an etching setup you can use.
Photo of a flex circuit etched using the exact same process as described below in step-by-step detail.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.