A novel electrostatic spring has been designed using triangle or inverted triangle shaped dielectrics that allow adjusting the spring constant by controlling the electric potential between a capacitor pair. Both tension as well as compression springs are possible. An experiment was performed verifying our analytical prediction for both configurations using 3D printed dielectrics demonstrating spring constants of tens of mN/m. This device may find application in areas of precision force measurements by always providing the optimum resolution independent of the applied load or in environments of very high temperatures above 1000 °C where classical springs fail.