Spring 2021 Distinguished Lecturer - Dr. Yoke Khin Yap | Michigan Tech Research Forum

University Professor Yoke Khin Yap

Lecturer

University Professor Yoke Khin Yap, Director of Applied Physics Graduate Program

Topic

Positive Use of Negative Properties at the Nanoscale | Recording of Yap Lecture | Passcode: 3we*mv!Y

Research Statement

The nanoscale is a measure of extremely small substances. For example, a nanometer (unit: nm) is one-billionth of a meter, equivalent to the length of a linear array of ten hydrogen atoms, the smallest atom on earth. My research group started with the synthesis and characterization of nanoscale materials, and has established a global leadership on boron nitride nanotubes (BNNTs). In this talk, I will demonstrate the use of undesirable properties of BNNTs for novel electronic and biomedical applications at the atomic and molecular scales. The lesson learned to me is to think positively about the negative aspects of things. This may lead to unexpected discoveries that most people missed.

Six Questions with Professor Yoke Khin Yap

You focus your work on the fundamentals of synthesis, characterization, and applications of functional materials. How did you come to choose this focus? Or, did it choose you?

My current research is an extension of my efforts developed during my PhD and postdoctoral training. Specifically, I focus on the synthesis, characterization, and application of materials constructed by boron (B), carbon (C), and nitrogen (N), the so-called B-C-N materials system. These are the smallest elements on earth to construct solids with strong covalent bonds (the type of chemical bond in diamonds, nanotubes, and graphene). The theme of B-C-N nanomaterials has earned me the prestigious NSF CAREER award in 2005.

How do your research and teaching complement each other?

Research, teaching, and educational outreach are integrated into my career at MTU. The first instrument that I purchased for my research lab at MTU was a high-power pulsed laser through a $50K REF Seed grant. This was used for pulsed-laser deposition (PLD) with a high-vacuum chamber that I designed for my PhD work. My PhD advisor gifted me the chamber before I moved from Japan to Houghton. Many of my key research work was produced by using this PLD system. In addition, I started to use the laser and the PLD chamber in laser workshops for undergraduate students in my optics class. On the other hand, to secure NSF research funding, I need to demonstrate the broader impacts of my proposed research. Therefore, courses and workshops on nanotechnology were developed to undergraduate and graduate students, as well as >400 local female high school students. Those are the examples of how my research and teaching complement each other.

What has changed the most in your field over the past decade (or two)?

There has been a lot of development in carbon nanomaterials, started from the one-dimensional (1D) carbon nanotubes (CNTs) and then the two-dimensional (2D) graphene (Nobel Prize in Physics 2010). In the past few years, research interest has extended to 2D materials beyond graphene (non-carbon layered materials). Although I did a lot of work on carbon nanomaterials, my major focus is not within this hot carbon field. Instead, my group focuses on boron nitride nanotubes (BNNTs), which are structurally similar to CNTs but different in properties. Interestingly, the research interest in 1D BNNTs and 2D BN nanosheets has gradually increased and become more substantial during the past few years. I am very proud to have contributed to the popularity of BN nanomaterials. Both carbon and BN materials belong to the B-C-N system that I focused on during the past two decades.

What is the biggest challenge in your fields of expertise?

The biggest challenge in experimental nanoscale research is the cost for precise nanoscale characterization. Most nanomaterials are constructed by hundreds of atoms. We need electron microscopy instruments to visualize the nanomaterials. We need nanoscale probes to measure the properties of the sample. All of these require expensive instruments, cleanroom, and extensive experience, which are lacking in many institutes including Michigan Tech. I have been struggling, especially during the first few years of my career. I managed to minimize these issues by collaboration and user projects in national nanoscience centers. I have also helped MTU in securing two major research instrumentation grants from NSF to purchase such instruments, including the current scanning transmission electron microscopy (S-TEM) system on campus that comes with unique sample probes/holders.

How does Michigan Tech work for you as a home base?

The department of physics, and Michigan Tech as a whole, are practicing welcoming, inclusive, and supportive atmosphere. These were very important to me when I was a junior faculty from Asia, who didn’t have any prior teaching, learning, and working experience in the U.S. In addition, the safe and small-town setting at Houghton (we have countable cars, and traffic lights here) allow me to focus well on my work. All of these work out very well to me as I always look positively on the “negative” aspects of things.

What's next in your research?

I will continue to explore unique phenomena at the atomic and molecular scales of materials at room-temperature. Many scientists are working at these scales at the cryogenic temperatures. Our recent work started to demonstrate that we can use nanomaterials to stabilize atomic and molecular structures for room-temperature applications. This is cutting edge for quantum phenomena. Furthermore, atomic and molecular scales are the right meeting points for experimental and theoretical scientists to collaborate, because nanoscale can be too big for many accurate theoretical modeling. All these will allow me to demonstrate fruitful experimental-theoretical work at the cutting edge of room-temperature quantum phenomena.