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Video s3
    Details
    Author(s)
    Display Name
    Kangni Liu
    Affiliation
    Affiliation
    University of Pittsburgh
    Affiliation
    Affiliation
    University of Pittsburgh
    Display Name
    Jonathan Rubin
    Affiliation
    Affiliation
    University of Pittsburgh
    Affiliation
    Affiliation
    University of Pittsburgh
    Abstract

    Biological neurons exhibit rich and complex nonlinear dynamics, which are computationally expensive and power-hungry for hardware implementation. This paper demonstrates the design and development of a hardware-friendly nonlinear neuron model based on an intuitive control theory perspective. The neuron consists of a mixed-feedback system operating at multiple timescales to exhibit a variety of modalities that resemble the biophysical mechanisms found in neurophysiology. The single neuron dynamics emerges from four voltage-controlled current sources and features spiking and bursting output modes that can be controlled using tunable parameters. The bifurcation structures of the neuron, modeled as a 4D dynamical system, illustrate the roles of sources acting on different timescales in shaping the neural dynamics. For the first time, a neural network test chip consisting of 6 nonlinear bio-mimetic neurons and 10 tunable synapses was designed on 180nm CMOS technology. A 4-neuron network with inhibitory synapses of increasing strength was verified to achieve coupled rhythms. The test chip has an area of 0.6mm x 2mm and consumes 0.753mW of total average power.