By removing the potentiometer from the SMC-01 and replacing it with
a bi-flex sensor, you can control the servomotor position by bending
the flex sensor. Applications for this are a glove based servo motor controller interface. To experiment with this tip application you may want to try connect passive resistive sensors to the SMC-01 to move and control the servomotor position, Try passive resistive sensors such as; photo-resistors, thermal resistors (thermistors), pressure sensors, magneto-resistive sensors, etc.
The potentiometer used in the SMC-01 is set at 20K. So passive resistive sensors the operated in the 0 to 30K range should fuction quite well. For passive sensors whose base line resistance is greater than this range, you can try placing the passive sensor in parallel with a variable resistor and adjust the variable resistor to see if you can obtain a reasonable scale factor to operate the servomotor.