Toray Industries Communicates Wirelessly Across UHF Band With a Printed Semiconductor
Toray Industries recently claimed that they were the first in the world to communicate wirelessly across the ultrahigh-frequency (UHF) band.
Toray Industries' design includes their own printed radio-frequency identifier (RFID), which employs a high-performance semiconductive carbon nanotube composite (CNT).
Such an achievement helps enhance work efficiency in retailing and logistics because it allows communication over long distances and performs batch readings of RFID sensors.
Carbon Nanotube Composites
Copper is a conventional material used as a conductor on circuit boards (including RFID). Copper has a low electrical resistance (and cost), but as copper electronics scale down in size and package density increases, the device may have lower reliability.
Carbon nanotubes (CNT) are known to work with or replace copper in electronic packaging applications. Image used courtesy of Britannica
According to Aryasomayajula et. al, carbon nanotubes (CNT) can be used in printed electronics as an alternative to copper. CNT are known for their high mechanical strength and excellent thermal and electrical properties in circuits, supercapacitors, and nanoscale sensors.
Research in this area has been explored by many researchers and labs, including Chavali et al. who constructed a wireless UHF-RF powered sensor operating at 433 MHz. This sensor, which included a gas-sensitive composite thin film made of PPy and modified multi-walled carbon nanotubes (MWCNTs), detected gases and volatile organic vapors.
Toray distinguishes itself from this research and others, claiming that their CNT design is the first in the world to suppress aggregation of signal-wall carbon nanotubes without inhibiting conductivity. Toray asserts they achieved this by attaching semi-conductive polymers on the surfaces of the nanotubes.
Toray states that their design is aimed at eventually providing a solution for high-cost integrated circuit (IC) chips. It is also designed to address the lack of electron mobility of just 20 cm2/Vs. The company's research on RFIDs with printed materials using CNTs has allowed Toray to reach electron mobility of 182cm2/Vs. High mobility can generally be regarded with faster responses in ICs.
Carbon nanotube composites. Image used courtesy of Toray Industries
Toray also fabricated an RFID prototype with a 24-bit memory that was able to communicate wirelessly with UHF waves over a distance of 20 cm—what they claim is the first in the world for a printed UHF RFID. Their goal is to materialize a 60-bit memory to promote product data collection and sharing to enhance supply chain efficiency.
The Future of RFID, IC, and Printed Circuit Design
This announcement addresses the future that engineers, researchers, and designers can look forward to—both within and outside RFIDs. Advancements being made with printed circuits using substrates, nanotubes, nanoparticles, and various organic and inorganic semiconductors will deliver a low-cost solution that is accessible in different applications such as wearables, RFID and IoT systems, and general industrial and consumer electronics.
Toray’s approach to manufacturing low-cost ICs and mounted-free printed semiconductors can set a precedent for future designs as it reduces extra steps, costs, and issues that can occur during the mounting process.
While traditional RFID systems offer a range of up to 100 m, Toray’s latest solution offers its promised performance while exploring several new fronts of research in electronics. Fully printed RFIDs have yet to be actualized, so this release shines a new light on more research to come.