Soft, Pliable, and Wireless Optical Sensor Opens New Possibilities in Imaging Technology at Osaka University

Wednesday - February 21 2024, 06:17 UTC - 9 months ago

Researchers at Osaka University have developed a flexible and wireless optical sensor using carbon nanotubes and organic transistors on an ultra-thin polymer film. This sensor is highly sensitive, works in a wide range of conditions, and can be attached to soft and curved objects, making it suitable for non-destructive analysis. Potential applications include non-destructive imaging, wearable devices, and soft robotics.

In an exciting development, researchers at Osaka University have created a soft, pliable, and wireless optical sensor using carbon nanotubes and organic transistors on an ultra-thin polymer film. This breakthrough has the potential to open up new possibilities in imaging technologies and non-destructive analysis techniques.

The field of imaging technology has made significant strides in recent years, from high-speed optical sensors that can capture over two million frames per second to compact, lensless cameras that can produce images with just a single pixel. The optical sensor is an essential component in any camera, as it senses the light that passes through the lens, similar to the retina in the human eye.

The sensors used in conventional optical sensors are typically made of inorganic semiconductors and ferroelectric materials, making them stiff and unable to bend. To overcome this issue, the researchers at Osaka University have developed a new way to detect light. Instead of traditional sensors, they use an array of tiny carbon nanotube photodetectors printed on an ultra-thin polymer substrate. When exposed to light, the nanotubes heat up, creating a thermal gradient that generates a voltage signal. Doping the nanotubes with chemical carriers during printing further enhances their sensitivity. This sensor can detect not only visible light but also infrared light, including those related to heat and molecules, making it versatile in various applications.

To organize the voltage signals into an image, the researchers also print organic transistors on the polymer substrate. The sensor does not need to be physically connected to a computer via wires to read the signals, as a wireless Bluetooth module is used instead. This feature allows for easy attachment to soft and curved objects for surface and internal analysis without causing any damage.

The researchers have successfully tested the prototype of the sheet-type optical sensor to sense heat from objects like human fingers or wires and even glucose flowing through tubes. The sensor has proven to be highly sensitive across a wide range of wavelengths, and it maintains its functionality even in harsh conditions, including room temperature and atmospheric conditions.

With its unique advantages, such as wireless measurement and high bending durability, this sheet-type optical sensor has the potential to simplify many tasks, such as evaluating the quality of liquids without the need to sample them. The researchers are confident that this innovation holds significant promise in numerous applications, including non-destructive imaging, wearable devices, and soft robotics.