  The full architecture of an electrostatic kinetic energy harvester (KEH)
based on the concept of near-limits KEH is reported. This concept refers to the
conversion of kinetic energy to electric energy, from environmental vibrations
of arbitrary forms, and at rates that target the physical limits set by the
device's size and the input excitation characteristics. This is achieved thanks
to the synthesis of particular KEH's mass dynamics, that maximize the harvested
energy. Synthesizing these dynamics requires little hypotheses on the exact
form of the input vibrations. In the proposed architecture, these dynamics are
implemented by an adequate mechanical control which is synthesized by the
electrostatic transducer. An interface circuit is proposed to carry out the
necessary energy transfers between the transducer and the system's energy tank.
A computation and finite-state automaton unit controls the interface circuit,
based on the external input and on the system's mechanical state. The operation
of the reported near-limits KEH is illustrated in simulations that demonstrate
proof of concept of the proposed architecture. A figure of $68\%$ of the
absolute limit of the KEH's input energy for the considered excitation is
attained. This can be further improved by complete system optimization that
takes into account the application constraints, the control law, the mechanical
design of the transducer, the electrical interface design, and the sensing and
computation blocks.
