A technology has been developed that can detect the contact of micro-glass tubes with light, and innovations in manufacturing technology and biotechnology are expected.

The Korea Electrotechnology Research Institute (KERI) Smart 3D Printing Research Team led by Dr. Jae-yeon Pyo announced on the 30th that they have developed a groundbreaking technology that can determine whether nanometer-sized micro-glass tubes are in contact using light.

A 'micro-glass tube' is a precision instrument with the end of a glass tube processed to a very small size (diameter 0.1mm to 0.000010mm), and is used as a key tool in various fields, from biotechnology that deals with cells to micro-electroplating and nano 3D printing.

Specifically, in biotechnology, it is used when injecting sperm into eggs during in vitro fertilization, or as a tool to invade cell walls for studying cell mechanisms.

In the field of electroplating, metal plating can be formed only in microscopic areas, so it can be used to produce precision electronic circuits or microscopic structures. If a glass tube is used as a 3D printing nozzle, ultra-fine structures can be printed in three dimensions.

The most important thing when using a micro-glass tube is to implement delicate and precise contact at the end so that the glass tube does not break or the target object is not damaged.

Previously, contact was confirmed by observing with an optical microscope, but for nanometer-scale ultra-fine glass tubes,However, due to the limitation of resolution, it was not possible to distinguish contact. There is also a method of determining contact using current or vibration, but there were problems such as limitations in the materials (conductors) that can be used, interference in the results, and variability.

The contact detection method used by Dr. Pyo Jae-yeon's team is 'light'. When light is shined on a micro-glass tube, the light is transmitted through the tube to the lower end.

At this time, when the tip does not touch the object, a clear light is emitted, and the moment it touches the object, it disappears. It is a very simple method that can determine contact beyond the limits of the resolution of an optical microscope by shining a single light, but it is an achievement that cannot be achieved without a comprehensive understanding of the interaction between light and matter in the nanometer range.

Through various experiments and simulations, the research team physically demonstrated that the light transmitted in the form of an evanescent wave is not scattered at the end due to contact, but is transmitted to the object it touches.

In addition, to verify the usability of the technology, the delicate contact discrimination of micro-glass tubes was demonstrated in various fields such as △nano 3D printing process △micro copper electroplating process and solving clogging of pipes △invasion of oral epithelial cells' cell walls, confirming accurate and immediate discrimination performance.

The results of the related research were recognized for their excellence and published as a cover paper in 'ACS Nano', a top-level SCI academic journal in the field of nanoscience published by the American Chemical Society. The 'JCR Impact Factor', which evaluates the influence of academic journals, is 15.8, which puts it in the top 5.9% in its field.

KERI's Dr. Pyo Jae-yeon explained, "The existing nano 3D printing process based on microscopic observation was facing physical limitations, so a completely new approach was needed to improve the resolution, stability, and yield of printing." He continued, "Based on our understanding of photophysical phenomena, we came up with a groundbreaking idea to utilize the micro-glass tube, a nozzle used in 3D printing, as a tool for contact discrimination, and we achieved good results."

KERI, which has completed the patent application for its original technology, expects that this achievement will receive much attention in various industrial fields such as 3D printing, display, biotechnology, electroplating, and semiconductors that require nanometer-level ultra-precision processes.

In particular, it is expected to have a very wide range of applications because it is an ultra-simple technology that can be implemented simply by shining a single light bulb without any material or environmental constraints. Dr. Pyo Jae-yeon's team plans to directly demonstrate and verify its usability in more fields, actively discover companies in demand, and promote technology transfer.

Meanwhile, KERI is a government-funded research institute under the National Research Council of Science and Technology of the Ministry of Science and ICT. This research was conducted through KERI’s basic project, ‘Development of 4D printing technology for integrated electrical and electronic device circuits/housing.’ Dr. Pyo Jae-yeon is also an associate professor at the University of Science and Technology (UST).