CMOS weak-inversion log-domain glycolytic oscillator: a cytomimetic circuit example

摘要

This paper presents a 3 V, 1.21μW subthreshold log-domain circuit which mimics the oscillations observed during the biochemical process of glycolysis due to the phosphofructokinase enzyme. The proposed electronic circuit is able to simulate the dynamics of the glycolytic oscillator and represent the time-dependent concentration changes of the reactants and the products of the chemical process based on nonlinear differential equations which describe the biological system. By modifying specific circuit parameters, which correspond to certain chemical parameters, good agreement between the biochemical and electrical model results has been reached. The paper details the similarities between the equations that describe the biochemical process and the equations derived from the circuit analysis of a transistor and a source-connected linear capacitor, a topology also known as the Bernoulli Cell. With the use of the Bernoulli Cell formalism, the chemical equations which describe the biochemical system have been transformed into their electrical equivalents. The analog circuit, which implements the whole process, has been synthesised, and simulation results including Monte Carlo analysis are provided, in order to verify the robustness of the proposed circuit and to compare its dynamics with prototype biological behaviour.