Hybrid Circuits with Nanofluidic Diodes and Load Capacitors

Abstract

The chemical and physical input signals characteristic of micro-and nanofluidic devices operating in ionic solutions should eventually be translated into output electric currents and potentials that are monitored with solid-state components. This crucial step requires the design of hybrid circuits showing robust electrical coupling between ionic solutions and electronic elements. We have studied experimentally and theoretically the connectivity of the nanofluidic diodes in single pore and multipore membranes with conventional capacitor systems for the cases of constant, periodic, and white noise input potentials. The experiments demonstrate the reliable operation of these hybrid circuits over a wide range of membrane resistances, electrical capacitances, and solution pH values. The model simulations are based on phenomenological equations that provide a convenient description of the electrical circuit operation. The results should contribute to advance signal transduction and processing using nanopore-based biosensors and bioelectronic interfaces.

Optimizing Energy Transduction of Fluctuating Signals with Nanofluidic Diodes and Load Capacitors

“…The process is experimentally robust and can be scaled up by using multipore membranes instead of single‐nanofluidic diodes . The hybrid network can be described theoretically by means of equivalent electrical circuits that permit to simulate the system response for each practical design . We will focus here on the case of polymeric nanopores but the concepts developed can also be implemented using solid‐state pores and ion channels …”

“…The hybrid networks with the half‐wave (HW) doubler, full‐wave (FW) doubler, and HW quadrupler permit to scale up the energy conversion process of Figure . The characteristics of the different elements in the networks can be found elsewhere . The single pore and multipore membranes incorporate ion tracks obtained from the irradiation of 12 µm thick polyimide (PI) and polyethylene terephthalate (PET) foils at the linear accelerator UNILAC (GSI, Darmstadt) that are converted into approximately conical pores by asymmetric track‐etching technique …”

“…B) The steady state capacitor voltages V st obtained at long times from the time‐dependent charging curves for the cases of the simple charging, HW and FW doublers, and HW quadrupler. The simulations are carried out using equivalent electrical circuits for each network design …”

“…Furthermore, the results for the HW quadrupler suggest that other optimization procedures can be implemented by appropriate design of the hybrid networks. Remarkably, the experimental data can be described theoretically in terms of equivalent electrical circuits that allow simple and accurate simulations of each network design.…”

“…In particular, we have demonstrated the conversion of fluctuating zero‐average external potentials into nonzero ionic currents, both in artificial and biological systems. These directional currents eventually produce robust electronic responses in hybrid networks with different interconnectivities submitted to white noise input signals …”