Mother nature provides the best ideas for the development of innovative, bio-inspired materials for medical engineering. In the following study, researchers utilized the outstanding properties of Chitin in combination with silk fibroin for preparation of an optically transparent hybrid material, inspired by the constituent of arthropods cuticles. The study moreover addresses the highly interesting and future-oriented applications, like the direct measurement of glucose content in the eye with smart contact lenses or scratch resistant display covers, using this biomimetric composite.
Biomimetic Chitin-Silk Hybrids: An optically transparent structural platform for wearable devices and advanced electronics
Hong M.-S., Choi G.-M., Kim J. et al. Advanced functional materials. 2017, 1705480. Doi: 10.1002/adfm.201705480
In this study, a hybrid material based on Chitin from squid pen and silk-fibroin from Bombyx Mori was produced using different methods (solution process, centrifugal casting, micromolding) to create films and contact lenses. Spectroscopic and surface analysis of the Chitin-Silk (CS) hybrids revealed the homogenous nanofibrous morphology of ultrafine Chitin nanofibers and silk β-sheets. The optically transparent hybrid material had a significantly increased mechanical toughness and was enzymatically biodegradable.
The authors present three very interesting applications of Chitin-Silk hybrids as structural and functional platform in the future.
- Integration of a wireless ocular sensor on a CS hybrid contact lens for glucose monitoring
- Manufacturing of a wireless, wearable heater by adding a silver nanofiber network onto a Chitin-Silk hybrid film by electrospinning
- Grasping motions had no influence on the temperature of the heater when applied to a human finger
- Temperature of the heater was adjustable via Bluetooth
- Scratch-Resistant Transparent Display Cover Window based on CSβ Hybrid Film. In the study, 35 µm thick CSβ Hybrid Films were coated with epoxy-siloxane hybrid material (EHL) on both sides by UV curing.
- Performance of a nanoscratch test using a diamond tip showed a higher scratch resistence for EHL-CSβ-hybrids compared to toughened glass and pure CSβ hybrid film
- Pencil hardness of 8H
- Wear test with steel wool (1 kgf/cm) leads to scratches on bare CSβ hybrid films but not on EHL-CS films after 200 cycles
Conclusion: Chitin nanofiber-silk fibroin hybrids were successfully developed and produced, showing beneficial characteristics like mechanical strength and optically transparency. The authors pointed out and tested promising applications for this biomimetic hybrid material.