‘Small Box’ Detecting Water Quality, Food Freshness, Nutrients, and Pharmaceutical Ingredients

Chongqing - With a 9-cm-long, 5-cm-wide, and 5.5-cm-high "small box," it is capable of detecting water quality, food freshness, nutrients, and pharmaceutical ingredients, said Professor Xie Huikai, the director of the BIT Microelectronics Institute (Beijing Institute of Technology's Chongqing Institute of Microelectronics and Microsystem).

The "small box" is a Micro-Electro-Mechanical System Fourier Transform Infrared Spectrometer, or  Micro FTS Spectrometer, developed independently by Professor Xie's team. It conducts non-destructive, real-time, online organic substance composition and concentration analysis.

Micro FTS Spectrometer. (Photo/BIT Chongqing Institute of Microelectronics and Microsystem)

The Micro FTS Spectrometer, known for its miniaturization, integration, and mass production, dominates the global tech sphere with versatile applications tailored to user needs, notably in fields like food and agriculture. 

Additionally, it holds a competitive price edge over imported alternatives, cutting downstream costs. Anticipated mass production and market launch are on track for the upcoming year.

Speedy and accurate, reduced waste liquid

Professor Xie highlighted that while traditional FTS spectrometers have core components the size of a 24-inch suitcase, the Micro FTS spectrometer fits in half of a lady's hand and weighs only 370 grams.

The Micro FTS Spectrometer has been employed for water quality analysis at a wastewater treatment plant for six months. "Using a Micro FTS Spectrometer to detect and analyze data is not only speedy but also highly accurate, resulting in reduced waste liquid," said Zheng Yuanliang, the person in charge of the sewage treatment plant in Shiban Town, Western (Chongqing) Science City. "For us, the cost is greatly reduced. This instrument is more cost-effective than imported equipment worth millions."

Chen Chao, an optical engineer at BIT Chongqing Institute of Microelectronics and Microsystem, added, "Our spectrometer can produce one valid spectral data within 10 seconds. It has collected and processed more than 4,000 samples data in six months, saving time for emergency response and preventing the spread of contamination."

Xie Huikai (left) discusses his work with team members in the lab. (Photo/BIT Chongqing Institute of Microelectronics and Microsystem)

Micromirror can be used in a broader range of scenarios 

The device utilizes the world's initial ultra-large displacement electrothermal MEMS micromirror and a distinctive optical design, notably boosting the resolution of the Fourier Transform spectrometer. It has attained global leadership in the core chip of the MEMS-based Micro FTS spectrometer.

The chip's stability is an important guarantee for the whole system. Since 2008, the team has searched for suitable materials for the chip, eventually finding a dual-material combination of metal and dielectric that meets the requirements.

Micro-FTS Spectrometer core. (Photo/Lei Jian)

The MEMS micromirror's performance and characteristics rely heavily on the chosen driving method. Xie's team opted for electrothermal power through numerous experiments, eschewing conventional methods such as electrostatic and electromagnetic drives.

"The chip's response time to drive signals has improved from 0.1 seconds initially to 0.01 seconds now," said Xue Yuan, a senior R&D engineer of MEMS at the institute. Such a drive ensures that the micromirror can be used in a broader range of scenarios as it can also achieve quick transformation in other application scenarios."

(Deng Yawen, as an intern, also contributed to this report.)