Tag Archives: Wei Li

Photonic cellulose nanocrystals (CNC) for flexible sweat sensor

It turns out there’s also a hydrogel aspect to this story about a flexible sweat sensor. As for cellulose nanocrystals (CNC), Canada played a leading role in the development of this nanomaterial and I have a bit more about the Canadian CNC scene later in this posting following the link and citation for the research paper. On to the research,

Highly elastic hydrogels constructed by heat-induced hydrogen bond remodeling can switch between wet and dry states (Image by ZHANG Fusheng and LI Qiongya)

A May 8, 2023 news item on phys.org features this work from the Dalian Institute of Chemical Physics of the Chinese Academy Sciences,

Cellulose nanocrystal (CNC), an emerging bio-based material, has been widely applied in fields such as electronics, bioplastics and energy. However, the functional failure of such materials in wet or liquid environments inevitably impairs their development in biomedicine, membrane separation, environmental monitoring, and wearable devices.

Now, a research group led by Prof. Qing Guangyan from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences [CAS] reported a sustainable, insoluble, and chiral photonic cellulose nanocrystal patch for calcium ion (Ca2+) sensing in sweat.

A May 4, 2023 Dalian Institute of Chemical Physics of the Chinese Academy Sciences press release (also on EurekAlert but published May 8, 2023), which originated the news item, provides more detail about the work,

The researchers developed a simple and efficient method to fabricate insoluble CNC-based hydrogels. They found that by utilizing intermolecular hydrogen bond reconstruction, thermal dehydration enabled the optimized CNC composite photonic film to form a stable hydrogel network in an aqueous solution. Moreover, they indicated that the hydrogel could be reversibly switched between dry and wet states, which was convenient for specific functionalization.

The introduction of functionalized molecules by adsorption swelling in a liquid environment resulted in a hydrogel with freeze resistance (–20°C), strong adhesion, good biocompatibility, and high sensitivity to Ca2+.

“This work is expected to facilitate the application of sustainable cellulose sensors to monitor other metabolites (i.e., glucose, urea, and vitamins, etc.),” said Prof. QING. “It also lays foundation for digitally controlled hydrogel systems operating in environment monitoring, membrane separation, and wearable devices.”

Here’s a link to and a citation for the paper,

Sustainable, Insoluble, and Photonic Cellulose Nanocrystal Patches for Calcium Ion Sensing in Sweat by Qiongya Li, Chenchen He, Cunli Wang, Yuxiao Huang, Jiaqi Yu, Chunbo Wang, Wei Li, Xin Zhang, Fusheng Zhang, Guangyan Qing. small DOI: https://doi.org/10.1002/smll.202207932 First published online: 13 April 2023

This paper is behind a paywall.

FPInnovations is a Canadian research and development (R&D) not-for profit organization that was instrumental in the development of CNC. (If memory serves, they are a spinoff from the University of British Columbia.) There are two Canadian CNC production facilities (that I know of): CelluForce in Québec and Blue Goose Biorefineries in Saskatchewan. I get more information about research into applications for CNC from other parts of the world while the Canadian scene remains mostly silent.