Systems and methods for controlling electrochemical processes

Abstract

A system is disclosed for controlling an electrochemical process. The system has a power source that is coupled to a power amplifier. The power amplifier is configured to provide an electromotive force (emf) signal, and a plurality of electrodes apply the emf signal to an electrochemical solution. A control element is configured to control the power amplifier such that the emf signal exhibits a predetermined frequency, amplitude, and duty cycle for reducing a thickness of the Nernst diffusion layer such that an operational parameter is set to a predetermined value.

1 . A system for controlling an electrochemical process, comprising:
 a power source;   a power amplifier coupled to the power source and configured to provide an electromotive force (emf) signal;   an electrochemical solution;   a plurality of electrodes positioned within the electrochemical solution for applying the emf signal to the electrochemical solution, wherein a voltage potential across the electrodes causes ions to flow in the electrochemical solution, and wherein the electrochemical solution forms a Nernst diffusion layer along a boundary while the ions are flowing in the electrochemical solution; and   a control element configured to control the power amplifier such that the emf signal exhibits a predetermined frequency, amplitude, and duty cycle for reducing a thickness of the Nernst diffusion layer such that an operational parameter of the system is set to a predetermined value, the control element further configured to control the power amplifier such that the emf signal is repetitively applied to the electrochemical solution via the electrodes at least until the operational parameter is set to the predetermined value, and wherein the operational parameter is selected from at least one of the group including: a thickness of the Nernst diffusion layer, a limiting current density, a power density, an overpotential voltage, an ionic resistance, an exchange current density, a surface concentration, a surface conductivity, and a surface morphology.   
     
     
         2 . The system of  claim 1 , wherein the control element is configured to control the power amplifier such that the emf signal exhibits the predetermined frequency, amplitude, and duty cycle and a predetermined damping factor for reducing the thickness of the Nernst diffusion layer such that the operational parameter of the system exhibits the predetermined value. 
     
     
         3 . The system of  claim 2 , wherein the emf signal comprises a damped sinusoidal wave superimposed on a direct current (DC) signal. 
     
     
         4 . The system of  claim 1 , wherein the emf signal comprises a sinusoidal wave superimposed on a direct current (DC) signal. 
     
     
         5 . The system of  claim 1 , wherein the boundary is along a surface of one of the electrodes. 
     
     
         6 . The system of  claim 1 , wherein the control element is configured to adjust at least one of the predetermined frequency, amplitude, and duty cycle based on a changing condition of the electrochemical process. 
     
     
         7 . The system of  claim 1 , wherein the electrochemical process is an electrolytic electrochemical process. 
     
     
         8 . The system of  claim 1 , wherein the electrochemical process is a galvanic electrochemical process. 
     
     
         9 . The system of  claim 1 , wherein the electrochemical process is a biological process. 
     
     
         10 . The system of  claim 1 , wherein the emf signal is applied in a first direction, and wherein the system further comprises:
 a second a power amplifier configured to provide a second emf signal;   a plurality of second electrodes for applying the second emf signal to the electrochemical solution in a second direction that is perpendicular to the first direction, wherein a voltage potential between the second electrodes causes second ions to flow in the electrochemical solution, and wherein the electrochemical solution forms a second Nernst diffusion layer along a boundary while the second ions are flowing in the electrochemical solution; and   a second control element configured to control the second power amplifier such that the second emf signal exhibits a predetermined frequency, amplitude, and duty cycle.   
     
     
         11 . A method for controlling an electrochemical system, comprising:
 determining a desired value for an operational parameter of the system;   generating an electromotive force (emf) signal;   providing a voltage potential across a plurality of electrodes positioned within the electrochemical solution thereby causing ions to flow in the electrochemical solution, wherein the electrochemical solution forms a Nernst diffusion layer along a boundary while the ions are flowing in the electrochemical solution;   determining, based on the desired value, a frequency, an amplitude, and a duty cycle for the emf signal to be applied to the electrochemical solution for reducing the Nernst diffusion layer such that the operational parameter is set to the desired value; and   repetitively applying the emf signal to the electrochemical solution via the electrodes until the operational parameter exhibits the desired value,   wherein the operational parameter is selected from at least one of the group including: a thickness of the Nernst diffusion layer, a limiting current density, a power density, an overpotential voltage, an ionic resistance, an exchange current density, a surface concentration, a surface conductivity, and a surface morphology.   
     
     
         12 . The method of  claim 11 , wherein the determining, based on the desired value, comprises determining a damping factor for the emf signal. 
     
     
         13 . The method of  claim 12 , wherein the emf signal comprises a damped sinusoidal wave superimposed on a direct current (DC) signal. 
     
     
         14 . The method of  claim 11 , wherein the emf signal comprises a sinusoidal wave superimposed on a direct current (DC) signal. 
     
     
         15 . The method of  claim 11 , wherein the boundary is along a surface of one of the electrodes. 
     
     
         16 . The method of  claim 11 , further comprising adjusting at least one of the frequency, the amplitude, and the duty cycle. 
     
     
         17 . The method of  claim 11 , wherein the electrochemical process is an electrolytic electrochemical process. 
     
     
         18 . The method of  claim 11 , wherein the electrochemical process is a galvanic electrochemical process. 
     
     
         19 . The method of  claim 11 , wherein the electrochemical process is a biological process. 
     
     
         20 . The method of  claim 11 , wherein the emf signal is applied in a direction parallel to a first axis, and wherein the method further comprises:
 generating a second emf signal;   providing a voltage potential across a plurality of second electrodes positioned within the electrochemical solution thereby causing ions to flow in the electrochemical solution; and   applying the second emf signal to the electrochemical solution via the second electrodes in a direction that is perpendicular to the first direction.   
     
     
         21 . The method of  claim 20 , wherein a frequency, an amplitude, and a duty cycle of the second emf signal are respectively equal to the predetermined frequency, amplitude, and duty cycle.