“A few days ago, TDK announced that it has developed a technology that can use ultrasonic waves to transmit data and energy, and even supports penetrating metal layer shielding. In this process, the piezoelectric material component converts electrical signals into mechanical vibrations to generate sound waves, and vice versa, it can also convert sound waves into vibrations. This effect allows the device to be recognized by the sensor and read out the data. In addition, it can also transmit energy in a closed metal layer or pipeline.
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A few days ago, TDK announced that it has developed a technology that can use ultrasonic waves to transmit data and energy, and even supports penetrating metal layer shielding. In this process, the piezoelectric material component converts electrical signals into mechanical vibrations to generate sound waves, and vice versa, it can also convert sound waves into vibrations. This effect allows the device to be recognized by the sensor and read out the data. In addition, it can also transmit energy in a closed metal layer or pipeline.
RFID has become a mature technology in the logistics field. However, there are restrictions in some cases. For example, a metal casing can provide protection against RFID radio waves and prevent the use of device identification and data transmission through non-contact communication, but this will also shield the radio. The piezoelectric technology developed by TDK can use sound waves instead of electromagnetic waves, so data transmission can be achieved even in environments with shielding challenges. By combining application-specific sensor mounts and acoustic transmission channels, new applications can be developed in system integration.
The product is formed by a structure composed of (outer) piezoelectric elements, adhesive layer, homogeneous metal plate, adhesive layer and (inner) piezoelectric elements (see Figure 1).
Figure 1: The principle of ultrasonic-based data transmission using two piezoelectric discs
On the surface of the metallized material, the stimulation of the voltage signal can change the thickness of the piezoelectric element in the range of +/- 3 nm. Therefore, in the range of 10 MHz, it can convert electrical signals into mechanical vibrations to excite sound waves on the surface of the material. The material will resonate in certain modes. For example, a metal plate exhibits narrow-band resonance at multiples of the wavelength of the sound wave in the material, with a notch in the middle, which looks like a resonant comb. Due to its geometry and material properties, piezoelectric elements can also resonate. Due to the elastic material properties of the adhesive layer, the superposition of these modes forms an acoustic transmission channel with a relatively flat passband. In this channel, the deep notch of the resonant comb disappears (Figure 2), allowing data transmission according to the Near Field Communication (NFC) standard.
Figure 2: At frequencies higher than 10.5 MHz, this results in areas where the attenuation is relatively low and constant, so that sound waves can be used for signal transmission.
Very low temperature change characteristics can meet more needs
The transmission channel has very low dependence on temperature and the uniformity or thickness of the metal material. This independence is due to the fact that the single peak and notch of the resonant comb in the communication window is less obvious than the frequency band outside this area (Figure 2). Since the NFC protocol standard applies to this acoustic channel, engineers can use chipsets that are already on the market. It can also protect data transmission from interference without affecting the channel. This protection makes it possible for applications that cannot be implemented using classic NFC technology.
NFC tag ICs support a variety of wireless sensor interfaces. These ICs have features such as I²C, power harvesting, and higher operating temperature ranges (eg-40 °C to +105 °C), which also help to quickly introduce this piezoelectric acoustic interface technology In a wide range of applications. This technology can transmit data through closed metal containers or even factory pipelines. It is also suitable for battery inspection in electric vehicles.
TDK made a demonstration to illustrate the function of this new technology, which can penetrate steel plates and perform data and energy transmission (Figure 3). Here, the environmental sensor in the metal container is responsible for collecting temperature, humidity and air pressure information. The air humidifier and fan heater provide data for the measurement. The data volume of the sensor is approximately 64 bytes, 12 measurements per second, resulting in a throughput of 6 kbps. In addition, 15 mW of power transmission can be used to operate sensors and additional microcontrollers.
Figure 3: This demonstration uses steel to transmit data and energy through ultrasonic waves.
Figure 4: Potential applications and advantages of piezoelectric ultrasound
A few days ago, TDK announced that it has developed a technology that can use ultrasonic waves to transmit data and energy, and even supports penetrating metal layer shielding. In this process, the piezoelectric material component converts electrical signals into mechanical vibrations to generate sound waves, and vice versa, it can also convert sound waves into vibrations. This effect allows the device to be recognized by the sensor and read out the data. In addition, it can also transmit energy in a closed metal layer or pipeline.
RFID has become a mature technology in the logistics field. However, there are restrictions in some cases. For example, a metal casing can provide protection against RFID radio waves and prevent the use of device identification and data transmission through non-contact communication, but this will also shield the radio. The piezoelectric technology developed by TDK can use sound waves instead of electromagnetic waves, so data can be transmitted even in environments with shielding challenges. By combining application-specific sensor mounts and acoustic transmission channels, new applications can be developed in system integration.
The product is formed by a structure composed of (outer) piezoelectric elements, adhesive layer, homogeneous metal plate, adhesive layer and (inner) piezoelectric elements (see Figure 1).
Figure 1: The principle of ultrasonic-based data transmission using two piezoelectric discs
On the surface of the metallized material, the stimulation of the voltage signal can change the thickness of the piezoelectric element in the range of +/- 3 nm. Therefore, in the range of 10 MHz, it can convert electrical signals into mechanical vibrations to excite sound waves on the surface of the material. The material will resonate in certain modes. For example, a metal plate exhibits narrow-band resonance at multiples of the wavelength of the sound wave in the material, with a notch in the middle, which looks like a resonant comb. Due to its geometry and material properties, piezoelectric elements can also resonate. Due to the elastic material properties of the adhesive layer, the superposition of these modes forms an acoustic transmission channel with a relatively flat passband. In this channel, the deep notch of the resonant comb disappears (Figure 2), allowing data transmission according to the Near Field Communication (NFC) standard.
Figure 2: At frequencies higher than 10.5 MHz, this results in areas where the attenuation is relatively low and constant, so that sound waves can be used for signal transmission.
Very low temperature change characteristics can meet more needs
The transmission channel has very low dependence on temperature and the uniformity or thickness of the metal material. This independence is due to the fact that the single peak and notch of the resonant comb in the communication window is less obvious than the frequency band outside this area (Figure 2). Since the NFC protocol standard applies to this acoustic channel, engineers can use chipsets that are already on the market. It can also protect data transmission from interference without affecting the channel. This protection makes it possible for applications that cannot be implemented using classic NFC technology.
NFC tag ICs support a variety of wireless sensor interfaces. These ICs have features such as I²C, power harvesting, and higher operating temperature ranges (eg-40 °C to +105 °C), which also help to quickly introduce this piezoelectric acoustic interface technology In a wide range of applications. This technology can transmit data through closed metal containers or even factory pipelines. It is also suitable for battery inspection in electric vehicles.
TDK made a demonstration to illustrate the function of this new technology, which can penetrate steel plates and perform data and energy transmission (Figure 3). Here, the environmental sensor in the metal container is responsible for collecting temperature, humidity and air pressure information. The air humidifier and fan heater provide data for the measurement. The data volume of the sensor is approximately 64 bytes, 12 measurements per second, resulting in a throughput of 6 kbps. In addition, 15 mW of power transmission can be used to operate sensors and additional microcontrollers.
Figure 3: This demonstration uses steel to transmit data and energy through ultrasonic waves.
Figure 4: Potential applications and advantages of piezoelectric ultrasound