One of the more far-out technologies on display at Sensors Converge is not yet in commercial production but has has been researched for years.
Someone uninformed might file it under the heading of “what’s it good for?” but this technology would help allow the reading of sensor data from inside closed metal chambers. Applications include gathering data from sensors inside metal chambers used in bio research or sensors inside metal pipes used widely in industrial settings where chemical reactions occur. Wireless safety data monitoring could even be possible with electric vehicle batteries when disconnected from a vehicle.
The point is that some metal casings cannot be opened to insert a probe for sensing data, like volume or temperature or pressure, without distorting the data reading or affecting the process inside the chamber. Electromagnetic waves like RFID radio waves cannot penetrate metal enclosures to make readings.
One display at TDK demonstrated how ultrasonic waves can be used to transmit data and energy. Using piezoelectrial materials glued to the inside and outside of a metal casing, TDK demonstrated engineers can convert electrical signals into mechanical vibrations to then excite acoustic waves that can be transferred through metal for detection.
TDK first described the process in late 2021 and its demonstration was only recently publicly available, TDK officials said.
The demo included a text description of “Wireless through-metal communication” and showed off small Acoustic Data Link devices to enable wireless data rates at up to 10kbit/second over NFC, with data transmissions through metal walls up to 50mm. (The metal on display was steel at 10mm but the concept works with brass and aluminum for now.) The devices can act as both transmitters and receivers that allow two-way communications on either side of a metal wall.
A demonstration of a closed chamber with a 10mm wall showed how a sensor inside the chamber was able to transmit light, humidity, pressure and movement data (via an axiometer) to a sensor outside the chamber, with the result registered on a remote display.
Biotech customers have indicated an interested in the technology for monitoring stem cell growth, while others have asked for flow-meter readings. Even a bike lock manufacturer has considered using the tech for operating the lock from inside to open it. TDK is still in the research phase of the tech and attended Sensors to find partners who might want to join in commercializing it, according to TDK booth personnel.