Researchers at the Drexel University School of Engineering have developed thin film devices fabricated by spray coating. This device can block electromagnetic radiation with the flip of a switch. Breakthroughs made possible by versatile two-dimensional materials called MXenes can tune the performance of electronic devices, enhance wireless connectivity, and protect mobile communications from intrusion.
A team led by Dr. Yury Gogotsi, a Bach professor at Drexel’s College of Engineering, has previously demonstrated a two-dimensional layered MXene material discovered more than a decade ago when combined with an electrolyte solution. Strong active shield against electromagnetic waves.This latest his MXene discovery reported at nanotechnology in natureshows how this shield can be adjusted when a small voltage (lower than that produced by alkaline batteries) is applied.
“Dynamic control of electromagnetic jamming has been a key technical challenge for protecting electronic devices and various other communication technologies operating at gigahertz frequencies,” said Gogotsi. “The number of wireless devices used in industry and the private sector has increased by orders of magnitude over the past decade, making this challenge correspondingly more urgent. This is why our findings, which dramatically mitigate, could have wide-ranging implications.”
MXene is a unique material in that it is highly conductive. They are great at reflecting microwave radiation, which can cause static electricity, feedback, and degrade the performance of communication devices. pass through.
This means that a thin coating on a device or electrical component prevents both them from emitting electromagnetic waves and from penetrating those emitted by other electronics. Eliminating the possibility of interference from both internal and external sources ensures the performance of the device, but when used for communication, some waves must be allowed to enter and exit.
“If you can’t control the rise and fall of electromagnetic waves in and around your device, it’s like a leaky faucet. said Mr. “Our shields ensure that the plumbing is tight. In other words, no electromagnetic radiation can leak in or out until you use the device.”
The key to unlocking the bi-directional tunability of the MXene’s shielding properties is to alternately expand and compress the space between the layers of the material, like an accordion, using ion flux and ejection to change the MXene’s surface chemistry. is to
Applying a small voltage to the film causes ions to penetrate or intercalate between the MXene layers, altering the surface charge and inducing electrostatic attraction. This changes the layer spacing, conductivity, and shielding efficiency of the material. When the ions are deintercalated, the MXene layer returns to its original state because the current is turned off.
The team tested 10 MXene and electrolyte combinations, each applied with a paint sprayer in a layer about 30 to 100 times thinner than a human hair. These materials have consistently demonstrated dynamic tunability of shielding efficiency in blocking microwave radiation, which is not possible with conventional metals such as copper and steel. The device also maintained its performance over more than 500 charge-discharge cycles.
“These results demonstrate that MXene films can be transformed from electromagnetic interference shielding to quasi-electromagnetic transparency by electrochemical oxidation of MXenes,” write Gogotsi and his co-authors. “MXene film could act as a dynamic EMI shielding switch.”
For security applications, Gogotsi suggests the MXene shield can hide the device from detection by radar and other tracking systems. The team also tested the possibility of a one-way shield switch. This allows the device to remain undetected and protected from unauthorized access until the device is deployed for use.
“One-way switches can be unprotected, allowing you to send a signal or initiate communication in an emergency or moment of need,” Gogotsi said. “This means that communication equipment can be protected from being affected or tampered with until it is used. can only be activated at
The next step for Gogotsi’s team is to explore combinations and mechanisms of additional MXene electrolytes to fine-tune the shield, resulting in stronger modulation of electromagnetic wave transmission and dynamic tuning to block radiation at different bandwidths. It’s about making it happen.
Original: Blocks radio waves and electromagnetic waves with a single switch
Than: Drexel University
