  We investigate how a single resonator with a time-modulated component
extracts power from an external ambient source. However, the collected power is
largely dependent on the precise choice of the modulation signal frequency. We
focus on the power absorbed from external vibration using a one
degree-of-freedom mechanical resonator where the damper has a time-varying
component. We show that time modulation can make a significant difference in
the amount of harvested power, leading to more than 10 times enhancement with
respect to an analogous system without time modulation. We also find that a
narrow band pair of peak and dip in the spectrum of the absorbed power occurs
because of the presence of an exceptional point of degeneracy (EPD). In this
narrow frequency range, the delay between the damper modulating signal and the
external vibrating signal largely affects the collected power. The high
frequency-selectivity of EPD-induced power management could potentially be used
in sensing and spectrometer applications.
