Device for ambient thermal and vibration energy harvesting
View Patent ↗An integrated circuit on a chip may include a plurality of capacitors that are connected in series and generate an AC noise signal. A selected bandwidth of the AC noise signal transmits through the series of capacitors as a first AC power signal. Respective rectifiers are positioned for receiving a positive cycle of the first AC power signal and a negative cycle of the first AC power signal. Output terminals are connected to the respective rectifiers and configured for connection to an off chip circuit. The capacitors may be fixed or variable gap capacitors.
1. An energy harvesting system, comprising:
a DC voltage source connected to a source of noise energy comprising a series of capacitors that generates an AC noise signal;
a selected bandwidth of the AC noise signal transmitting through the series of capacitors as a first AC power signal;
respective diodes rectifying the first power signal to charge a positive cycle storage capacitor and a negative cycle storage capacitor with the first AC power signal,
wherein the first AC power signal is rectified through a reverse biased diode during a negative cycle of the first AC power signal to produce an output power signal transmitted to the negative cycle storage capacitor;
wherein the first AC power signal is rectified through a forward biased diode during a positive cycle of the first AC power signal to produce a respective output power signal transmitted to the positive cycle storage capacitor, and
wherein the diodes are paired as a sub-unit and the sub-unit is connected to a positive cycle metal trace connection and a negative cycle metal trace connection, and the sub-units are repeated with respective connections to the positive cycle metal trace connection and the negative cycle metal trace connection.
2. The system of claim 1 , wherein a respective capacitor in the series of capacitors is configured with storage capacity of 1 pico-Farad.
3. The system of claim 1 , wherein the forward biased diode and the reversed biased diode are connected to additional diodes in a Cockcroft-Walton full-wave rectifier and multiplier circuit.
4. The system of claim 1 , wherein the series of capacitors comprises variable gap capacitors generating both the first AC power signal from the AC noise signal and a second AC power signal from a variable gap capacitor discharge cycle.
5. The system of claim 1 , wherein respective capacitors in the series of capacitors are fully charged by the DC voltage source to a stable state.
6. The system of claim 1 , wherein the diodes are selected based on the rate of conductance to match the series of capacitors as a noise source.
7. The system of claim 1 , wherein the AC noise signal comprises conductivity due to conductive carrier defect hopping through the capacitor.
8. The system of claim 1 , wherein the DC voltage source provides a voltage that corresponds to turn on voltages for the diodes.