Inexpensive chip-based device may transform spectrometry

October 23, 2018, Massachusetts Institute of Technology
A collection of mini-spectrometer chips are arrayed on a tray after being made through conventional chip-making processes. Credit: Felice Frankel

Spectrometers—devices that distinguish different wavelengths of light and are used to determine the chemical composition of everything from laboratory materials to distant stars—are large devices with six-figure price tags, and tend to be found in large university and industry labs or observatories.

A new advance by researchers at MIT could make it possible to produce tiny spectrometers that are just as accurate and powerful but could be mass produced using standard chip-making processes. This approach could open up new uses for spectrometry that previously would have been physically and financially impossible.

The invention is described today in the journal Nature Communications, in a paper by MIT associate professor of materials science and engineering Juejun Hu, doctoral student Derek Kita, research assistant Brando Miranda, and five others.

The researchers say this new approach to making spectrometers on a chip could provide major advantages in performance, size, weight, and power consumption, compared to current instruments.

Other groups have tried to make chip-based spectrometers, but there is a built-in challenge: A 's ability to spread out light based on its wavelength, using any conventional optical system, is highly dependent on the device's size. "If you make it smaller, the performance degrades," Hu says.

Another type of uses a mathematical approach called a Fourier transform. But these devices are still limited by the same size constraint—long optical paths are essential to attaining high performance. Since high-performance devices require long, tunable optical path lengths, miniaturized spectrometers have traditionally been inferior compared to their benchtop counterparts.

Instead, "we used a different technique," says Kita. Their system is based on optical switches, which can instantly flip a beam of light between the different optical pathways, which can be of different lengths. These all-electronic optical switches eliminate the need for movable mirrors, which are required in the current versions, and can easily be fabricated using standard chip-making technology.

By eliminating the moving parts, Kita says, "there's a huge benefit in terms of robustness. You could drop it off the table without causing any damage."

By using path lengths in power-of-two increments, these lengths can be combined in different ways to replicate an exponential number of discrete lengths, thus leading to a potential spectral resolution that increases exponentially with the number of on-chip . It's the same principle that allows a balance scale to accurately measure a broad range of weights by combining just a small number of standard weights.

As a proof of concept, the researchers contracted an industry-standard semiconductor manufacturing service to build a device with six sequential switches, producing 64 spectral channels, with built-in processing capability to control the device and process its output. By expanding to 10 switches, the resolution would jump to 1,024 channels. They designed the device as a plug-and-play unit that could be easily integrated with existing optical networks.

The team also used new machine-learning techniques to reconstruct detailed spectra from a limited number of channels. The method they developed works well to detect both broad and narrow spectral peaks, Kita says. They were able to demonstrate that its performance did indeed match the calculations, and thus opens up a wide range of potential further development for various applications.

The researchers say such spectrometers could find applications in sensing devices, materials analysis systems, optical coherent tomography in medical imaging, and monitoring the performance of optical networks, upon which most of today's digital networks rely. Already, the team has been contacted by some companies interested in possible uses for such microchip spectrometers, with their promise of huge advantages in size, weight, and , Kita says. There is also interest in applications for real-time monitoring of industrial processes, Hu adds, as well as for environmental sensing for industries such as oil and gas.

Explore further: A fresh sensation in sensing technology

Related Stories

A fresh sensation in sensing technology

June 1, 2018

The Internet of Things (IoT) is a technology classification that includes home appliances and other items embedded with electronics, software, sensors, and actuators that connect and exchange data. One key IoT technology ...

Recommended for you

New targets in the battle against antibiotic resistance

November 16, 2018

Bacteria are increasingly resistant to available antibiotics. A team of chemists from the Technical University of Munich (TUM) have now identified important enzymes in the metabolism of staphylococci. Blocking these enzymes ...

AI heralds new frontiers for predicting enzyme activity

November 16, 2018

Researchers from the Departments of Chemistry and Engineering Science at the University of Oxford have found a general way of predicting enzyme activity. Enzymes are the protein catalysts that perform most of the key functions ...

7 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Anonym843210
1 / 5 (3) Oct 23, 2018
hello viewers all over the globe am very happy today to share my testimony on how i was cure from HERPES disease, i have been suffering from herpes for the pass 9 months which makes me had constant pain all over my body, i have went to several hospitals taking treatment from doctors, but still know improvement till i meet a old friend of mine who direct me to a great traditional herbalist called Dr abaka which i contacted by email so luckily he reply back i explain my problem to him and he told me not to worry that his going to prepare the herbal medicine and send to me which will cure me forever, i believed in him, after all the procedures given to me by Dr abaka few weeks later i went to see my doctor to confirm if i was finally cure, the result was positive am totally cured by this great herbalist called Dr abaka, my life is more important now am free and happy if you have such sickness or any kind of disease contact Dr abaka details: drabakaspelltemple@gmail.com or call +23490632
scotteric
1 / 5 (1) Oct 23, 2018
I was diagnosed of herpes 3 years, and ever since then i have been taking treatment to prevent outbreaks, burning and blisters, but there was no improvement until i came across testimonies of Dr. Okasi on how he has been curing different people from different diseases all over the world, then i contacted him. After our conversation he sent me the medicine which i took according to his instructions for up to 3 weeks. After completing the medication i went back to my doctor for another test and the virus was all gone and i was completely cured, since then i have not had any signs of outbreak. I'm so filled with joy. With herbal medication Herpes Virus is 100% curable. I refer Dr Okasi to everyone out there with the virus Email: okasiherbalsolution@outlook.com, website: okasiherbalsolution.webs.com
Anonym247151
1 / 5 (1) Oct 26, 2018
Good news My people. I want to thank Dr. Ofure Herpes. Medicine is a good herbal medicine for the HERPES virus. I was diagnosed with the HERPES virus last month, and was looking for a solution to cure. Fortunately, I saw a testimony about how Dr. Ofure CURE HERPES VIRUS I decided to contact Dr. Ofure I contacted him He prepared a portion of herbal medicine and sent it to me, I started herbal medicine for my health. He gave me step by step instructions on how to apply it, when I applied it as instructed, I was cured of this deadly herpes virus within 2 weeks, now I am negative Ofure . My brother and sister I do not know that there are so many people who have the same herpes virus, please Dr. Ofure to help him too, and help me to thank Dr. Ofure for healing me, I am cured by Dr. Ofure Medicine, his email Contact: drfureherbalhome@gmail.com Cell Whatsapp Number +2348162868851. Dr Ofure also has the cure for HIV / AIDS, psoriasis, cancer,HBP, HPV may God bless you sir for your good works.
Anonym114265
not rated yet Nov 08, 2018
I had genital herpes for 5 years with so many outbreaks, and it affected my life. People think herpes is really a minor skin irritation, but it has long term effects on health. The stigma attached to this virus by ignorant people is ridiculous. Most people have herpes in one form or another, I was first taking antiviral medicines such as acyclovir (Zovirax), famciclovir, and valacyclovir (Valtrex), but no help.
I started using Herpes herbal remedy i purchased from Best Health Herbal Centre march this year. After using it for a month and two weeks, my condition changed automatically, all my symptoms are fully in control, no more outbreak and My family doctor confirm am genital herpes free last two months and Am now living a happy life. All thank to Best Health Herbal Centre, i will never stop telling the world about your good work.....To know more about Best Health Herbal Centre visit besthealthherbalcentre .com Thanks.
Anonym708893
not rated yet Nov 13, 2018
Good news My people. I want to thank Dr. OMOLOWA, Herpes. Medicine is a good herbal medicine for the HERPES virus. I was diagnosed with the HERPES virus last month, and was looking for a solution to cure. Fortunately, I saw a testimony about how Dr. OMOLOWA, CURE HERPES VIRUS I decided to contact Dr. OMOLOWA, I contacted him He prepared a portion of herbal medicine and sent it to me, I started herbal medicine for my health. He gave me step by step instructions on how to apply it, when I applied it as instructed, I was cured of this deadly herpes virus within 2 weeks, now I am negative OMOLOWA . My brother and sister I do not know that there are so many people who have the same herpes virus, please Dr. OMOLOWA to help him too, and help me to thank Dr. OMOLOWA for healing me, I am cured by Dr. OMOLOWA Medicine, his email Contact: dr.omolowa@gmail.com OR Cell Whatsapp Number +2349039377739. Dr OMOLOWA also has the cure for HIV / AIDS, psoriasis, cancer,HBP, HPV may God bless you sir for
Jan Gunter
not rated yet Nov 13, 2018
Am very glad to share this testimony with everyone for the marvelous work Dr Osifo has done for my life, 6 months ago i was diagnosed with herpes virus and ever since then i have been very unhappy, i was so down broken everyday, until one day when i came across a shocking testimony about how Dr Osifo cured someone of his herpes virus, without wasting much time i contacted him immediately on his email address: drosifoherbalcenter@gmail.com and after i explain myself to him about how terrible i have been, and he assure me that he will help me to cure my herpes virus,after he has prepared the herbal medicine he sent it to me and when i have received it and started using it i was totally cure within 2 weeks, i am forever grateful to Dr Osifo for helping me out with his herpes prescription that cured my virus. contact his email address: drosifoherbalcenter@gmail.com or you can call or whatsApp his Mobile number:+2348074876448..
Jan Gunter
not rated yet Nov 13, 2018
Am very glad to share this testimony with everyone for the marvelous work Dr Osifo has done for my life, 6 months ago i was diagnosed with herpes virus and ever since then i have been very unhappy, i was so down broken everyday, until one day when i came across a shocking testimony about how Dr Osifo cured someone of his herpes virus, without wasting much time i contacted him immediately on his email address: drosifoherbalcenter@gmail.com and after i explain myself to him about how terrible i have been, and he assure me that he will help me to cure my herpes virus,after he has prepared the herbal medicine he sent it to me and when i have received it and started using it i was totally cure within 2 weeks, i am forever grateful to Dr Osifo for helping me out with his herpes prescription that cured my virus. contact his email address: drosifoherbalcenter@gmail.com or you can call or whatsApp his Mobile number:+2348074876448..

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.