**5. The use of harvester with magnetic processing for simultaneous transmission of power and information through the supra-acoustic wave**

The use of smart materials for wireless power transmission (and information) proved to be practical, and the results obtained during the research indicated the high efficiency of this method. Following further work, the project of Smart Ultrasonic Resonant Power System (SURPS) was created, which provides for the possibility of such transmission via various media and through various transmitterreceiver configurations. Diagrams are shown in **Figure 14**.

The mechanism of energy transmission consists in "sending" mechanical energy through the actuator in the form of a pure, sinusoidal ultrasonic wave and then its "pickup" by the harvester through the magneto- or electrostatic material that is in it. In this way, energy (along with information) can be transmitted not only through different types of centers but also at different distances. The type of frequency modulation (FM) was used for transmission of information, which for the needs of various types of structures was modified so that the data transfer was less than the resonant frequency of the structure. This method worked well during laboratory tests, and a flow chart is shown in **Figure 14**. **Figure 15A** shows a schematic diagram of data sent by an actuator based on Terfenol-D (AT) or piezoelectric material (AP). **Figure 15B** in turn shows the signal that is obtained on a harvester with a core of magnetostrictive material. **Figure 15C** illustrates the result of the operation of the station with two magnetostriction rails and transducers from **Figure 16**. A sinusoidal carrier frequency with small harmonic distortion (in the below 23 kHz case) generated by an actuator for data transmission to a harvester-powered microprocessor is modulated in the "on-off" mode, that is, in some time fragments, the actuator does not work by temporarily disconnecting the power supply of the harvesting side. Due to the fact that the harvester power supply has been equipped with a bank of capacitors with a capacity of 0.5 s microprocessor operation without harvest rami support, satisfactory results have been achieved even when transmitting many bytes of information encoded in accordance with ASCII signs.

Simultaneous supply of the sensory system was obtained, based on an industrial 32-bit microprocessor system and data transmission in half-duplex mode at the speed of about 1000 bps with the recovery of energy from mechanical vibrations with an over-acoustic frequency. A technique for feeding the microprocessor system from harvester machines combined with various configurations at carrier frequencies depending on the natural frequency of the structure containing dedicated actuators and harvester units with electromagnetic and magnetostriction transducers was developed.

**Figure 16** shows a view of the assembled rail system with magnetostriction transducers with the possibility of powering the microprocessor system on the harvester side and transferring data in both directions.

**51**

**Figure 15.**

*Energy Harvester Based on Magnetomechanical Effect as a Power Source for Multi-node Wireless…*

One of the main assumptions of the two rails' system was to set the required prestress, within a single structure, obtained by means of plastic elements, separately with each magnetostrictive transducer. This resulted in mutual mechanical coupling of the actuator and harvester and the possibility of adjusting the resonance fre-

*Diagram of data sent (A) and received (B) by elements of the SURPS system. AT/P, actuator based on* 

**Figure 17** shows the difference in the structure of the actuators based on magnetostriction and piezoelectric transducers. The characteristic differences relate to the way of generating the signal that powers the given actuator. In the case of magnetostrictive devices, in which the induction coil is loaded, the basic problem is to obtain a sufficient level of magnetostriction at a current that does not overheat the magnetic circuit with the core. Piezoelectric actuators require a voltage of 200VRMS, which is obtained through a bandwidth transformer with a primary winding matched to the power level based on the M-type metal-oxide semiconductor field-effect transistor (MOSFET) configuration in the H-configuration. During the development of the SURPS system, a structure of certain stages of electro-

Based on the assumptions described above, as well as the current state of knowledge in the field of ultrasonic, wireless power transmission, a complete transceiver

*DOI: http://dx.doi.org/10.5772/intechopen.85987*

quency lying in the over-acoustic band.

*Terfenol-D/piezo material; HT, harvester based on Terfenol-D.*

magnetostrictive actuators and harvester was developed.

**Figure 14.** *A schematic diagram of power transmission through ultrasonic vibrations.*

*Energy Harvester Based on Magnetomechanical Effect as a Power Source for Multi-node Wireless… DOI: http://dx.doi.org/10.5772/intechopen.85987*

#### **Figure 15.**

*A Guide to Small-Scale Energy Harvesting Techniques*

**wave**

ASCII signs.

ers was developed.

**5. The use of harvester with magnetic processing for simultaneous transmission of power and information through the supra-acoustic** 

proved to be practical, and the results obtained during the research indicated the high efficiency of this method. Following further work, the project of Smart Ultrasonic Resonant Power System (SURPS) was created, which provides for the possibility of such transmission via various media and through various transmitter-

The mechanism of energy transmission consists in "sending" mechanical energy through the actuator in the form of a pure, sinusoidal ultrasonic wave and then its "pickup" by the harvester through the magneto- or electrostatic material that is in it. In this way, energy (along with information) can be transmitted not only through different types of centers but also at different distances. The type of frequency modulation (FM) was used for transmission of information, which for the needs of various types of structures was modified so that the data transfer was less than the resonant frequency of the structure. This method worked well during laboratory tests, and a flow chart is shown in **Figure 14**. **Figure 15A** shows a schematic diagram of data sent by an actuator based on Terfenol-D (AT) or piezoelectric material (AP). **Figure 15B** in turn shows the signal that is obtained on a harvester with a core of magnetostrictive material. **Figure 15C** illustrates the result of the operation of the station with two magnetostriction rails and transducers from **Figure 16**. A sinusoidal carrier frequency with small harmonic distortion (in the below 23 kHz case) generated by an actuator for data transmission to a harvester-powered microprocessor is modulated in the "on-off" mode, that is, in some time fragments, the actuator does not work by temporarily disconnecting the power supply of the harvesting side. Due to the fact that the harvester power supply has been equipped with a bank of capacitors with a capacity of 0.5 s microprocessor operation without harvest rami support, satisfactory results have been achieved even when transmitting many bytes of information encoded in accordance with

Simultaneous supply of the sensory system was obtained, based on an industrial

32-bit microprocessor system and data transmission in half-duplex mode at the speed of about 1000 bps with the recovery of energy from mechanical vibrations with an over-acoustic frequency. A technique for feeding the microprocessor system from harvester machines combined with various configurations at carrier frequencies depending on the natural frequency of the structure containing dedicated actuators and harvester units with electromagnetic and magnetostriction transduc-

**Figure 16** shows a view of the assembled rail system with magnetostriction transducers with the possibility of powering the microprocessor system on the

harvester side and transferring data in both directions.

*A schematic diagram of power transmission through ultrasonic vibrations.*

receiver configurations. Diagrams are shown in **Figure 14**.

The use of smart materials for wireless power transmission (and information)

**50**

**Figure 14.**

*Diagram of data sent (A) and received (B) by elements of the SURPS system. AT/P, actuator based on Terfenol-D/piezo material; HT, harvester based on Terfenol-D.*

One of the main assumptions of the two rails' system was to set the required prestress, within a single structure, obtained by means of plastic elements, separately with each magnetostrictive transducer. This resulted in mutual mechanical coupling of the actuator and harvester and the possibility of adjusting the resonance frequency lying in the over-acoustic band.

**Figure 17** shows the difference in the structure of the actuators based on magnetostriction and piezoelectric transducers. The characteristic differences relate to the way of generating the signal that powers the given actuator. In the case of magnetostrictive devices, in which the induction coil is loaded, the basic problem is to obtain a sufficient level of magnetostriction at a current that does not overheat the magnetic circuit with the core. Piezoelectric actuators require a voltage of 200VRMS, which is obtained through a bandwidth transformer with a primary winding matched to the power level based on the M-type metal-oxide semiconductor field-effect transistor (MOSFET) configuration in the H-configuration. During the development of the SURPS system, a structure of certain stages of electromagnetostrictive actuators and harvester was developed.

Based on the assumptions described above, as well as the current state of knowledge in the field of ultrasonic, wireless power transmission, a complete transceiver

#### **Figure 16.**

*View of the system of two rails with marked actuator and a unit recovering energy from mechanical vibrations (a) model, (b) real construction.*

#### **Figure 17.**

*Specification of the individual sections of the actuator: magnetostrictive (A), electrostatic element (B).*

system was designed based on a suitable microcontroller, attendance modulators, as well as dedicated software.

The main features of the SURPS system are:


**53**

**Figure 18.**

*The frequency response of the double bus system.*

*Energy Harvester Based on Magnetomechanical Effect as a Power Source for Multi-node Wireless…*

• Scanning of a given frequency range using the actuator-harvester system with

• Data transmission between the actuator and return harvester sections (Tx, Rx).

• Frequency range from 0.1 to 50,000 Hz, 0.1 Hz (used direct digital synthesis

As a model microprocessor system, a Silicon Laboratory solution called Gecko with a 32-bit Cortex-M3 processor with the designation EFM32TG840 was used. In all applications, this type of set was used, and the solution had to guarantee the ability to supply this system as typically industrial with simultaneous halfduplex transmission (data transmission in one direction at a time in a bidirectional

Data transfer is carried out using our algorithmy which we called frequency double frequency amplitude modulation (F2F-AM). As a result, the flow of information is much lower than the resonant frequency caused by ultrasounds or the structure itself and can get up to 1000 bps. Higher information flow rates can be

**Figure 18** shows the frequency response of the mechanical structure of **Figure 16**. It is noteworthy that the highest performance (highest voltage) is in the over-acoustic range (above 20 kHz). The "SW" zone means an acceptable range of resonance frequencies lying near 20 kHz. On the characteristics with a dashed line, the 2.5 V voltage value is marked to guarantee the start of the microprocessor system. The points "A" and "B" marked on the waveform correspond to the most favorable ranges of carrier frequencies; it means that there are more frequencies capable of powering the system, and depending on the needs, the desired ranges of carriers can be selected. It is also possible to work more microprocessors connected to the same harvester but activated by a strictly defined frequency. The latter option allows the described solution to be used in

• Reading the current root mean square (RMS) voltage from the harvester.

• The system is equipped with the possibility of generating signals for two actuators generating vibrations of the same frequency but shifted in phase

*DOI: http://dx.doi.org/10.5772/intechopen.85987*

real-time performance readout.

generator (DDS) Analog Devices AD9851).

obtained by using other types of frequency modulation.

with each other.

SHM applications.

channel).

*Energy Harvester Based on Magnetomechanical Effect as a Power Source for Multi-node Wireless… DOI: http://dx.doi.org/10.5772/intechopen.85987*


**Figure 18** shows the frequency response of the mechanical structure of **Figure 16**. It is noteworthy that the highest performance (highest voltage) is in the over-acoustic range (above 20 kHz). The "SW" zone means an acceptable range of resonance frequencies lying near 20 kHz. On the characteristics with a dashed line, the 2.5 V voltage value is marked to guarantee the start of the microprocessor system. The points "A" and "B" marked on the waveform correspond to the most favorable ranges of carrier frequencies; it means that there are more frequencies capable of powering the system, and depending on the needs, the desired ranges of carriers can be selected. It is also possible to work more microprocessors connected to the same harvester but activated by a strictly defined frequency. The latter option allows the described solution to be used in SHM applications.

As a model microprocessor system, a Silicon Laboratory solution called Gecko with a 32-bit Cortex-M3 processor with the designation EFM32TG840 was used. In all applications, this type of set was used, and the solution had to guarantee the ability to supply this system as typically industrial with simultaneous halfduplex transmission (data transmission in one direction at a time in a bidirectional channel).

Data transfer is carried out using our algorithmy which we called frequency double frequency amplitude modulation (F2F-AM). As a result, the flow of information is much lower than the resonant frequency caused by ultrasounds or the structure itself and can get up to 1000 bps. Higher information flow rates can be obtained by using other types of frequency modulation.

**Figure 18.**

*The frequency response of the double bus system.*

*A Guide to Small-Scale Energy Harvesting Techniques*

**52**

**Figure 17.**

**Figure 16.**

*(a) model, (b) real construction.*

well as dedicated software.

The main features of the SURPS system are:

system was designed based on a suitable microcontroller, attendance modulators, as

*View of the system of two rails with marked actuator and a unit recovering energy from mechanical vibrations* 

*Specification of the individual sections of the actuator: magnetostrictive (A), electrostatic element (B).*

• Operation of piezoelectric actuators/harvester and magnetic processing.

• Finding and generating the resonance frequency of mechanical construction.
