Researchers develop new glowing touchscreen that works underwater

imeng.vip:03月-10日

A schematic representation of an optical display system using mechanoluminescence and mechanical quenching in afterglow luminescent particles

Optical properties of afterglow luminescent particles (ALPs) in mechanoluminescence (ML) and mechanical quenching (MQ) have received a lot of spotlight. Recently, scientists have noted that it can impact several technological applications. It is also known to be widely applicable in many fields, and this has made it a gem.

A research team has received significant attention after making a groundbreaking development in optical display technology. These researchers, led by Professor Sei Kwang Hahn, are from Pohang University of Science and Technology (POSTECH). Members of this team included Ph.D. candidate Seong-Jong Kim from the Department of Materials Science and Engineering at the POSTECH. 

Together, the team uncovered a remarkable optical phenomenon with ALPs, which aids in underwater writing and the erasure of messages. The researchers are the first to create a device that could successfully implement this phenomenon.

Afterglow luminescent particles (ALPs) are materials with optical properties that can trap the irradiated photon energy in defect states. It then releases this absorbed energy gradually and displays it as light. The APLs exhibit mechanoluminescence when subjected to external physical pressure. It also undergoes mechanical quenching when the light fades away. 

Other scientists have actively researched and studied this technology for optical displays. However, the mechanism has been elusive. International journal ‘Advanced Functional Materials” featured the team’s findings in its recent publication. Hence, the team made history as the first to have made such findings in APLs.

Research team develops a new communication method underwater
For this research, the team examined the trapped irradiated photon energy in their defect states and recharging on both mechanoluminescence and quenching. They could successfully decipher the different mechanisms controlling the phenomena.

With this knowledge, the team combined the APLs that could successfully realize both phenomena with PVDF-HFP, a thin polymeric material. With this process, the team created an optical display patch that can be attached to the human skin.

This creation by the team could effectively pass information through writing by simply applying a little pressure with the finger. Similarly, exposing the patch to ultraviolet rays could easily reset it to its blank state. 

In this display patch made by the POSTECH team, the touchscreen shows strong resistance to humidity. When submerged underwater for prolonged periods, the display patch maintains functionality and performs every necessary operation. With this display patch, the research team has enabled more accessible underwater communication. 

Professor Sei Kwang Hahn, who led the research, stated, “It could serve as a communication tool in situations with limited communication options, such as underwater environments characterized by low light or high humidity.” He remarked, “It would also be used for wearable photonic biosensors and phototherapy systems in extreme environments.”

Professor Sei Kwang Hahn’s research team conducted this POSTECH-published research with financial support from several bodies. They included the Basic Research Program, the Korea Medical Device Development Fund, the Biomedical Technology Development Program of the National Research Foundation of Korea, and POSCO Holdings.