Fig. 7: Amplifier for ECG monitoring.

a Illustration of the ECG monitoring using an analog amplifier made of the intrinsically flexible ACNT circuits. b Output signals of the amplifier showing as many as 100 times of signal amplification (Vpp = 40 mV, Vdd = 1, 3, and 5 V). c Amplifier output with various input signal frequencies of 10–50 Hz (Vdd = 0.5 V).