Putting a ‘third eye’ in our pockets
Imagine you’re trying to know if the apple you bought two weeks ago is still good.
Now, imagine you can scan it with your phone and it’ll tell you.
Tsinghua University professor Bao Jie has developed a small spectrometer that can literally identify bad apples in the bunch.
It can also diagnose skin disease and detect air pollution, among other functions.
Dozens of companies have approached Bao since he founded the company QuantaEye in Beijing in late 2016.
Spectrometers measure changes in light when it interacts with matter in ways that detect more than the naked eye. They’ve long been used in research, but their size had previously hampered their applications for daily use.
Bao’s team developed one as small as a coin. It may cost only a few dollars once mass produced.
“Everyone will have a ‘third eye’ to see hidden realities,” the 34-year-old scientist says.
They were able to shrink the device using quantumdot nanotechnology.
Quantum dots, which were discovered in the early 1980s, are semiconductor crystals that are just a few nanometers in size. They absorb different light wavelengths when their size changes.
Bao got the idea of using this feature to create miniature spectrometers when he was doing post-doctoral research with Moungi Bawendi at the Massachusetts Institute of Technology in the United States from 2010 to 2013.
“Bawendi is one of the leading researchers of quantum dots, but he hadn’t looked into such applications before,” Bao says. “So I proposed my idea. He supported it.”
Before he went to MIT, Bao earned a bachelor’s degree at Tsinghua University and his doctorate in chemistry at Brown University between 2006 to 2010.
He returned to Tsinghua in 2014 through the country’s Young Thousand Talents program that recruits young experts from overseas.
The research paper Bao and Bawendi co-authored was published by the academic journal Nature in July 2015.
“Most current microspectrometers rely on interference filters and interferometric optics that limit their photon efficiency, resolution and spectral range,” the editor’s note reads.
“Jie Bao and Moungi Bawendi have developed an efficient, cost-effective microspectrometer that overcomes many of these limitations ... and points to possible application in space exploration, surgical and clinical ‘lab-ona-chip’ settings.”
Bao has also worked with Tel Aviv University’s Michael Gozin Group to develop an artificial nose based on the quantum-dot spectrometer. It’ll give more accurate and quantitative olfactory information than police dogs or master sommeliers.
The scientist says that what impressed him most about his experiences in the US is that students have more freedom to choose classes and research fields, while Chinese education was still rigid 10 years ago.
He uses this approach with his Tsinghua students.
Bao’s PhD student Sun Si says: “He didn’t test my knowledge but rather my passion when he interviewed me.”
Li Simin, Bao’s doctoral student, says: “Bao encourages us to find our own interests in research and life.”
She recalls Bao once told her and other students the story of Steve Jobs. Completing a PhD is a process of connecting the dots in life — what you have studied before will finally assist your research, Bao says.
Bao learned how to hold a gun steady when he joined a marksmanship club as a sophomore. He later used this experience to assemble the mini spectrometer’s prototype, which required arranging about 200 quantum dots on a small microchip.
He’s working with a team of over 30 researchers to optimize and mass produce the device.
“I am not satisfied with going from zero to one,” Bao says.
“I want to do things from zero to 99. There’s always room for improvement.”
I want to do things from zero to 99. There’s always room for improvement.” Bao Jie, scientist