The surge of interest in flexible and wearable electronics over the past few years has increased the amount of time and money dedicated to developing their components. Although flexible screens and transistors have seen significant development, flash memory has not been able to replicate this progress.
The function of flash memory depends on its dual dielectric layers. Dielectrics are electrical insulators that can also be polarized through the application of an electric field. Finding a dielectric material with adequate flexibility has been a challenging task for researchers. Due to these constraints, a flash memory that simultaneously exhibits high performance and flexibility has yet to be developed.
However, the research teams led by Professor Seunghyup Yoo of the School of Electrical Engineering and Professor Sung Gap Im of the Department of Chemical and Biomolecular Engineering have found a solution through their collaborative efforts. Through a process called initiated Chemical Vapor Deposition (iCVD), the teams were able to produce polymers that possess the necessary characteristics.
iCVD, which is one of Professor Im’s main research interests, is an innovative technique that produces thin polymer films. The process starts with vaporizing (via heat or the reduction or air pressure) the required monomers and a compound called the initiator. The vaporized compounds are introduced into a vacuum chamber containing the substrate or material on top of which the polymer will be formed. Due to the difference in temperature between the vapor and the substrate, the monomers connect and form the polymer at the surface of the substrate with the help of the initiator.
The method allowed the team to produce organic, insulating polymer films that showed satisfactory levels of flexibility and, once installed in a flash memory, optimal performance. Previous flash memories that utilized insulating polymer films required a voltage of at least 100V to operate adequately. However, the excessive voltage led to the memories deteriorating within a month of use. The flash memory produced by Professor Yoo’s team showed exceptional performance even at a voltage as low as 10V. It is predicted that the memory can last at least 10 years when operating at this voltage. Furthermore, compared to existing flash memories that utilizes inorganic insulation films and can only withstand a mechanical strain rate of 1%, the newly produced memories endured at a significantly higher rate of 2.8%. The research teams were also able to demonstrate their findings by successfully installing their flexible flash memories in both 6-μm plastic films and basic printer paper.
Professor Yoo stated, “This research affirms the possibility of high flexibility, high performance flash memory and contributes towards the development of legitimate wearable electronic devices, smart electronic papers, and more.”