  Neuromorphic engineering is a rapidly developing field that aims to take
inspiration from the biological organization of neural systems to develop novel
technology for computing, sensing, and actuating. The unique properties of such
systems call for new signal processing and control paradigms. The article
introduces the mixed feedback organization of excitable neuronal systems,
consisting of interlocked positive and negative feedback loops acting in
distinct timescales. The principles of biological neuromodulation suggest a
methodology for designing and controlling mixed-feedback systems
neuromorphically. The proposed design consists of a parallel interconnection of
elementary circuit elements that mirrors the organization of biological neurons
and utilizes the hardware components of neuromorphic electronic circuits. The
interconnection structure endows the neuromorphic systems with a simple control
methodology that reframes the neuronal control as an input-output shaping
problem. The potential of neuronal control is illustrated on elementary network
examples that suggest the scalability of the mixed-feedback principles.
