Capacitance C= e A/d or C=Q/V Energy stored in the capacitor W=0.5CV^2
This a straight forward problem W=0.5 e A/d (V^2) W=0.5 x 4.5 x 4.75 x 10^-9 m^2 / 8.5 x 10^-9 m= W=...
since d is the thickness and the energy is inversely proportional to energy stored in the capasitor then with the increase of the thickness of the membrane the energy will decrease.
