Study on Vibration Energy Harvesting with Small Coil for Embedded Avian Multimedia Application

Abstract

We have developed an electromagnetic generator to bury in subcutaneous area or abdominal cavity of the birds. As we can't use a solar battery, it is extremely difficult to supply a power for subcutaneous implantation such as biosensors under the skin due to the darkness environment. We are aiming to test the antigen-antibody reaction to confirm an avian influenza. One solution is a very small generator with the electromagnetic induction coil. We attached the developed coil to chickens and pheasants and recorded the electric potential generated as the chicken walked and the pheasant flew. The electric potential generated with physical simulator is equal to or exceeds the 7 V peak-to-peak at maximum by 560/min of flapping of wings. Even if we account for the junction voltage of the diode (200 mV), efficient charging of the double-layer capacitor is possible with the voltage doubler rectifier. If we increase the voltage, other problems arise, including the high-voltage insulation of the double-layer capacitor. For this reason, we believe the power generated to be sufficient for subcutaneous area of birds. The efficiency, magnetic 2 mm in length and coil 15mm in length, if axial direction is rectified, the magnetic flux density given to the coil could calculated to 7.1 % and generated power average 0.47mW. The improvements in size and wire insulation are expected in the future.

Fig. 1. The principle of central magnet float, the aircurrent from the central hole provides the stability ofdirection of axis.

Fig. 2. Hand-operated coil, 0.03mm copper 6100 times.

Fig. 3. A magnet inside and set OPAMP (AD623) forthe differential amplification.

Fig. 4. Connection diagram of the differentialamplification.

Fig. 5. Development a physical simulator for flap ofbirds.

Fig.6. Generated voltage with flapping 480.

Fig. 7. The result of the FFT of Fig. 6.

Fig. 8. Relationship generated voltage and flapping.

Fig. 9. Relationship between generated power and loadresistance(R).

Fig. 10. Coil on flying Japanese Pheasants at SeisaUniversity Oiso campus.

Fig. 11. Generated electrostatic potential full span.

Table 1. Specifications of the magnet, use as a columnar magnet connected tandemly four (column of total 8mm in length).