Made a 3D setup with 3D printed curves. One curve is static fastened to the floor of the setup, while the other is fastened to a servo to control rotational motion. Silicone castred skin will be fastened to the front so that the skin is stretched a bit when the moving curve is moved away from center. 

The servo is controlled by a simple arduino code with max and min limits for movement, which can be easily changed.

#include <Servo.h>

Servo myservo;  // create servo object
int pos = 0;    // storing servo position

void setup() {
  myservo.attach(9);  // standard to use pin 9 for servo
}

void loop() {
  for (pos = 0; pos <= 35; pos += 1) { // 0 to 35 degrees with steps of 1 degree
    myservo.write(pos);              // go to pos
    delay(15);                       // waits to reach pos
    Serial.print(pos);				// write to serial monitor to see results
  }
  for (pos = 35; pos >= 0; pos -= 1) {
    myservo.write(pos);             
    delay(15);                      
    Serial.print(pos);
  }
}