Time-variant electrical equivalent circuit of a dry bacteriorhodopsin sensor

Validation of a time-variant electrical equivalent circuit for a dry bacteriorhodopsin sensor

“…1, nor any of the reported equivalent circuits can be used to calculate the component values for simulating the changes in photocurrent responses caused by illumination of the sensor. This is despite the fact that this change in the response has been reported in the literature [7], [17], [16] and in our previous studies [19], [20].…”

“…This early modeling was based on the presumption that the system is a linear timeinvariant system. However, it has been reported in the literature [7], [18], [16] and in our previous studies [19], [20] that the time constants of the photoelectric response vary in dry bR sensors depending on whether the sensors are under the effect of incident light or not.…”

“…Different electrical equivalent circuits for bR sensors have been proposed in the literature [4], [15], [19], [22]. Common to all these models is that the photoelectromotive force Ep is connected to the measurement instrumentation through a series capacitance CP.…”

“…2 Recently, Wang et al [18], Walczak [7], and Miyazaki et al [16] have reported that the bR capacitance varies depending on the illumination of the bR sensor. Our previous measurements [19] found that the time constant varies and that it cannot be modeled by a linear time-invariant (LTI) model.…”

“…In this paper, we focus on validating an electrical equivalent circuit we proposed in [20] for dry bR sensors when the intensity of the incident light is varied. Unlike earlier models, the proposed model considers also the illumination on the bR sensor.…”