Cytomorphic Electronic Systems: A review and perspective

The boltzmann-exponential thermodynamic laws govern the noisy molecular flux in chemical reactions as well as the noisy subthreshold electron current flux in transistors. These common mathematical laws enable one to map and simulate arbitrary stochastic biochemical reaction networks in highly efficient cytomorphic systems built on subthreshold analog circuits. Such simulations can accurately and automatically model noisy, nonlinear, asynchronous, stiff, and nonmodular feedback dynamics in interconnected networks in physical circuits. The scaling in simulation time for stochastic networks with the number of reactions or molecules is constant in cytomorphic systems. By contrast, it grows rapidly in digital systems, which are not parallelizable. Therefore, cytomorphic systems enable large-scale supercomputing systems-biology simulations of arbitrary and highly computationally intensive biochemical reaction networks that can nevertheless be compiled via digitally programmable parameters and connectivity.