Abstract: A closed-loop controlled chemical apparatus includes: a compound sensor including: an analyte sensor and that: produces, by the analyte sensor, a voltage signal; a reference sensor in electrical communication with the analyte sensor; a transistor including a gate terminal such that a drain current of the transistor is maintained at a constant value and operated at an optimal transduction condition of peak sensitivity and minimum noise of the transistor; a feedback controller in electrical communication with the transistor and that: receives a transduction signal; determining a deviation of the transduction signal from a setpoint, the setpoint determined by transfer characteristics of the transistor; produces the feedback control signal that minimizes the deviation of the transduction signal from the based on a control model; and communicates the feedback control signal to the reference sensor for suppression of electrical noise fluctuations in the closed-loop controlled chemical apparatus.

Abstract: A charge detector includes: a charge sensor that senses a charged analyte and produces a charge signal in response to contact with the charged analyte; a transducer in electrical communication with the charge sensor and that: receives the charge signal from the charge sensor, receives a feedback control signal; and produces a transduction signal in response to receipt of the charge signal and the feedback control signal; and a sensitivity controller in electrical communication with the transducer and that: receives the transduction signal from the transducer; produces the feedback control signal in response to receipt of the transduction signal from the transducer; and produces a charge readout in response to receipt of the transduction signal from the transducer.

Abstract: A closed-loop controlled chemical apparatus includes: a compound sensor including: an analyte sensor and that: produces, by the analyte sensor, a voltage signal; a reference sensor in electrical communication with the analyte sensor; a transistor including a gate terminal such that a drain current of the transistor is maintained at a constant value and operated at an optimal transduction condition of peak sensitivity and minimum noise of the transistor; a feedback controller in electrical communication with the transistor and that: receives a transduction signal; determining a deviation of the transduction signal from a setpoint, the setpoint determined by transfer characteristics of the transistor; produces the feedback control signal that minimizes the deviation of the transduction signal from the based on a control model; and communicates the feedback control signal to the reference sensor for suppression of electrical noise fluctuations in the closed-loop controlled chemical apparatus.

Abstract: A charge detector includes: a charge sensor that senses a charged analyte and produces a charge signal in response to contact with the charged analyte; a transducer in electrical communication with the charge sensor and that: receives the charge signal from the charge sensor, receives a feedback control signal; and produces a transduction signal in response to receipt of the charge signal and the feedback control signal; and a sensitivity controller in electrical communication with the transducer and that: receives the transduction signal from the transducer; produces the feedback control signal in response to receipt of the transduction signal from the transducer; and produces a charge readout in response to receipt of the transduction signal from the transducer.

Abstract: A spin transport channel includes a dielectric layer contacting a conductive layer. The dielectric layer includes at least one of a tantalum oxide, hafnium oxide, titanium oxide, and nickel oxide. An intermediate spin layer contacts the dielectric layer. The intermediate spin layer includes at least one of copper and silver. The conductive layer is more electrochemically inert than the intermediate spin layer. A polarizer layer contacts the intermediate spin layer. The polarizer layer includes one of a nickel-iron based material, iron, and cobalt based material. The conductive layer and intermediate layer are disposed on opposite sides of the dielectric layer. The dielectric layer and the polarizer layer are disposed on opposite sides of the intermediate spin layer. The intermediate spin layer is arranged to form a conducting path through the dielectric layer configured to transport a plurality of electrons. Each of the plurality of electrons maintains a polarized electron spin.