NASA Ames Research Center
- B.S. Chemistry, Fudan University, China
- M.S. Materials Science and Engineering, University of Utah
- Ph.D. Materials Science and Engineering, University of Utah
"I am working on nanotechnology based intelligent sensing systems for space missions and terrestrial applications."
Advice to Students:
"Find intern opportunities as early as possible either at universities or outside of school."
Q: When did you first find that your career path focused on nanotechnology?
Li: I have worked on the development of chemical sensors for the past 20 years. In the early year of my career I usually used conventional materials for chemical sensors. In 2001, I started looking for materials that can provide better performance for chemical detection. I searched the website and found out that carbon nanotubes have some unique chemical and physical properties that are useful for my need. I also found that the Center for Nanotechnology at NASA Ames was the largest nanotechnology group in the world at that time, where scientists were working on carbon nanotubes synthesis and characterization. I called and tried to get some carbon nanotubes for improving my chemical sensors. Unexpectedly, I got a job offer from NASA in November 2001 and started to work on nano chemical sensors since then.
Q: What current nanotechnology applications are you working on?
Li: I am currently working on nanodevices for chemical sensing. The sensing device is a silicon based array chip with up to 64 channels. Different nanostructured materials, such as carbon nanotubes and nanowires, are deposited onto each channel that provides a unique interaction with a chemical exposed. A pattern of sensing signals from all channels in the array is used for discriminating different chemicals for detection. It is just like using the fingerprint to identify people. This type of sensing device is also called electronic nose that can mimic human or dog’s nose to smell chemicals. The nanosensing devices can find applications in space missions, e.g. fuel leak detection at the launch pad, cabin air monitoring in international space station (ISS), trace chemical detection in the planetary exploration. These nanosensing devices can also be used for terrestrial applications, such as defense and homeland security, industrial process control, environmental monitoring, and medical diagnosis at the point of care.
Q: What's the most rewarding thing about working with nanotechnology?
Li: I feel rewarded when I see the technology I developed can find real world use to improve the quality of life in our society as well as find use in space missions. It is amazing to see our effors of digging in things in extreme small size at nanoscale level can then find their applications in the other extreme in size such as space or universe. I developed a nanotechnology based sensing device containing an array of nanosensors that was launched in space in 2007 for trace chemical detection. Two of my nanosensors were in JPL electronic nose platform that was deployed in the international space station for cabin air monitoring in November 2008. These are truly exciting opportunities and rewarding to me.
Q: Is there an example you can provide that shows how something you’ve worked on has positively impacted the world?
Li: Lately, I have been leading a team to develop a sensor for homeland secrity under the department of homeland security (DHS) Cell-All program. We have developed a sensing module in compact size with low power consumption that can be plugged in to an iPhone for chemical sensing. The sensor array chip in the module is made using a group of nanostructured materials, selected to provide high sensitivity, selectivity, fast response and low power consumption. The sensing information can be communicated via 3G or Wi-Fi network. The overall device is the size of a postage stamp that can be carried anywhere for chemical sensing at anytime. They can be used by firefighters or first responders to make decision at the point of detection; they can be used at home for gas leak detection; they can be used by doctors and patients at the point of care or at home to monitoring the biomarkers in the breath that link with certain diseases.
Q: What do you think is the single greatest impact nanotechnology has had on the world thus far?
Li: Nanotechnology is not a new market or industry. Its impact penetrates in many scientific disciplines and commercial sectors. So far, we see the great impact of its wide coverage, not yet in a single aspect of scientific or technology revolution. Looking at the migration from conventional technology to micro-technology that has produced the computers and internet which caused the information revolution, it is hard to predict what type of revolution will come from nanotechnology.
Q: Please give an example of what you envision nanotechnology applications leading to in the future.
Li: Nanotechnology will provide unique materials properties with small, light, low power characteristics that can enable new materials and more tools for improving our quality of life. I believe that nanotechnology will lead the research and applications in biology and life science to a new arena. For example, the use of nanostructured materials for controlled drug release and delivery; the active implantation of nanoprobes in brain for remediation of Parkinson’s disease; nanosensors for cancer detection.
Q: Do you find yourself working more in a team situation, or more alone?
Li: Nowadays, the research and technology development are getting more and more sophisticated. Nobody can work on her/his own. Teamwork is necessary; especially when we work in the nanotechnology field, many disciplines are involved in the research and technology development.
Q: If you work more as a team, what are some of the other areas of expertise of your team members?
Li: As I said before, I am working on the nanosensors development. This nanosensor technology requires the expertise from many different areas: chemistry, materials science, physics, mathematics, electronics and electrical engineering, computer sciences, mechanical engineering, environmental science and engineering. This list can go on when the nanosensors are used for different applications.
Q: Did your university training help you in your nanotechnology work?
Li: My university training helped me a lot in my nanotechnology work. I view the training helped me in two ways: one is the fundamental understanding of the materials from molecular level to their structures, their chemical and physical properties and their applications; another one is more important that the university training gave me a key to open the door to the science and technology. During my college years, I felt that I was exposed to an ocean of knowledge. There are so many things that you can learn and/or you should learn. You are like a sponge with huge capacity to absorb the new stuff and start to think about to create some new stuff. Actually, I feel that I need to learn more when I know more because I see more that I don’t know.
Q: Do you have a mentor? Did you in your college years?
Li: I don’t have an official mentor, nor did I have in the college. Fortunately, I have worked closely with Dr. Meyya Meyyappan and other people both inside NASA and outside NASA in the past 7-8 years. I have learned a lot about nanotechnology both in theory and in experiments. Lifelong learning has helped me to get my knowledge deeper and wider, which enables me to be creative and to develop new sensor technology for real world applications to improve the security, safety and quality of life.
Q: If you had to do it all over again, would you still focus on nanotechnology applications?
Li: Yes, it is so exciting to work on nanotechnology because it has shown so many potentials that this technology can improve today’s technologies to a step further with better performance. Nanotechnology impacts our daily life in many ways from cloths, food, cosmetic products, paints, tools, medicine and other things.
Q: What advice do you have for pre-university students?
Li: I would encourage them to study in a solid way and expose themselves to many different types of science and technology areas. Playing an important role in nanotechnology requires a set of skills, not just one or two. They should find intern opportunities as early as possible either at universities or outside of school. Involving in a project can train students to get hands-on experience and problem solving skills, become a team player and a creative people. Both intelligence and integrity are important for being a successful scientist and/or technologist.