Fig 1.
Anatomy of the Aloe Vera Plant.
In this figure, (a) shows the physical outlook of an Aloe Vera, (b) shows the cross-section of an Aloe Vera leaf, (c) shows the Aloe Vera rind layer, (d) shows the Aloe Vera latex layer and (e) shows the inner semi-solid fleshy gel of the Aloe Vera.
Fig 2.
The parallel connection among 20 leaves from 3 pots of Aloe Vera plants.
Fig 3.
Block diagram of the energy harvesting system.
Fig 4.
Schematic of the proposed power management circuit connected to Aloe Vera.
Fig 5.
Circuit diagram of boost converter during (a) ton (b) toff.
Fig 6.
Schematic of the receiver circuit with micro-controller connected to temperature and humidity sensor.
Table 1.
Voltage measured when varying numbers of electrode-pairs connected in series into a leaf.
Table 2.
Voltage and current measured from 20 Aloe Vera leaves connected in parallel connection.
Fig 7.
Increment of VCin during the charging of the input capacitor for the first time.
Fig 8.
Comparison of VCin and VCout when the rectifier is excluded from the circuit versus when the rectifier is included in the circuit.
(A) shows the waveform of VCin and VCout when the rectifier is excluded from the circuit. (B) shows the magnification of the waveform during the transmission time, ton when the rectifier is excluded from the circuit. (C) shows the waveform of VCin and VCout when the rectifier is included in the circuit. (D) shows the magnification of the waveform during the transmission time, ton when the rectifier is included in the circuit.
Fig 9.
Performance characteristic of the self-oscillating boost converter.
(a) shows the output voltage VCout and VCin of the power management circuit under no-load condition during the operation of the self-oscillating boost converter. (b) shows the switching characteristic of the SW switch during the operation of the self-oscillating boost converter under no-load condition.
Fig 10.
The VCin and VCout waveforms when the power management circuit is connected to the transmitter load.
(a) indicates the changes in VCin. (b) indicates the variation of VCout. (c) portrays the active transmission time, ton when the transmitter load is triggered. (d) portrays inactive transmission time, toff when the transmitter load is not triggered.
Fig 11.
Temperature and humidity measured by the DHT 11 sensor.