Iin = 1e-7:1e-5:1e-3;
Vout = Iin*0; 
for i = 1:100
   calib_stiff(Iin(i));
   Vout(i) = stiffener('Vout','constant',1,Iin(i));
end
Vsipm = Vout-Iin*10e3;
plot(Iin,real(Vsipm),Iin,Vout);
