I performed dilation on signal but the peak values of signal are not increasing.

I performed dilation (mathematical morphology operation) on signal. But the peak values of signal is not increasing. Kindly give any suggestion in my code to perform proper dilation. The voltage and time values are imported from excel file.

 %Selecting structuring element
sel=strel('square',11)
%voltage values of signal 
signal1 = voltage
%Dilation on voltage signal
results1=imdilate(signal1,sel);
%Time values of signal
signal2 = time
%dilation on time siganl
results2=imdilate(signal2,sel);
plot(signal2,signal1,results2,results1)
xlabel('Time (seconds)')
ylabel('Voltage')
legend('orignalsignal','dilated')