South Korean researchers have successfully conducted a study that will change … our faces: they mix carbon, polymer and solvents to get a special printing ink that we can use. This translates the supercapacitors onto a contact lens with microscopic precision, through a technique called “direct ink”. They have proven that the technology is viable, and could turn it into smart contact lenses with health sensors in the future.
Basically, thanks to this new ink formula, we can put supercapacitor technology and wireless charging capabilities into contact lenses.
Although smart glasses have not yet become a new trend in technology, when the technology is modern enough to have augmented reality contact lenses attached directly to the eyes, we are likely to think differently. And yet, such a contact lens that can read our tears parameters will become a great health monitoring tool; By analyzing tears, we also find diseases such as glaucoma and diabetes.
A volunteer is wearing smart contact lenses, the picture on the right is when he underwent a heat test, seeing how the contact lenses emitted heat.
Prior to that dream, researchers need to find a way to power this contact lens device, so that it can display images, analyze data and desired functions. other. It was obvious that the power cord could not be plugged directly into the eye, so they needed a way to wirelessly transmit power.
Researchers Jang-Ung Park from Yonsei University and Sang-Young Lee from the Ulsan National Institute of Science and Technology have found a solution: a flexible, small and supercapacitor device and an antenna. Collect power to charge the whole system.
“The available supercapacitors are manufactured in the form of multiple sheets stacked in cylindrical or square compartments, making them too bulky and rigid to fit into a tiny contact device,Professor Park explained. “The breakthrough we achieved was to create a kind of supercapacitor that can print out a special ink. The prints will appear at the edge of the contact lens, so they will not affect the view of the user.”
The researchers have shown that the microscopic direct ink (DIW) technique is accurate enough to draw circuit components on a small device. The challenge is to find an ink that gives the right electrical characteristics, but also has to be flexible enough to make ink.
To make supercapacitors, the researchers mixed activated carbon with multilayer carbon nanotubes (MWCNT) with PVP and PVDF resins, all mixed in organic solvents.
Structure of test contact lenses.
To make the electrolyte, the researchers combined an organic ion solution with a thiol-ene monomer. After the DIW technology drew the necessary circuits, the team used ultraviolet light to “memorize” the entire system, and then put the entire ionic solution into a plastic frame.
To charge the device remotely, the team of scientists placed an antenna made of silver nanofibre made of electrospin (filament only 400 nm in diameter) and silver nanowires made of mass spectrometry technology – electrospray (wire with diameter of 15-25 nm). They use silicon as a detector in the antenna.
In the test, this contact lens can withstand a 30% stretch on both sides. The results for both the rabbit and the human were also very positive: the contact lenses were comfortable and very safe, able to maintain a stable temperature when wireless charging and when performing the light test.
However, the research stops here – at the level that tells us that the technology is workable; Supercapacitor devices are not enough to “carry” the requirements of a smart contact lens, such as displaying images for eyes to see or tears analysis.
“Our supercapacitors are only suitable for electric devices that need fast charging to operate within minutes,Professor Lee said. “VFor longer devices, we still need a different type of battery, so more research is still needed.”
Refer to PhysicsWorld