From a hemoglobin protein to a tiny, engineered scaffold

The distinctive low weight and high strength properties of carbon fibers make them a popular structural choice in many electrical, mechanical, and chemical applications. Three-dimensional carbon fiber networks have shown promise recently in electrodes for energy storage and cell scaffolds in tissue engineering. Surface area texturing can further improve the performance of these carbon structures.

However, conventional nano-texturing methods rely on volatile chemicals which are environmentally unfriendly and may cause unexpected—and sometimes explosive—reactions during application.

Hayashi et al. developed an eco-friendly, optical method of fabricating 3-D carbon fiber networks with textured surfaces from an aerogel.

Using pyrolysis, the team converted bovine-derived hemoglobin protein into a carbon foam with thin walls and dense struts. Next, the aerogel was irradiated with a series of very short, femtosecond, laser pulses.

“Due to the incredibly high intensity of our laser, the very thin sheets are blown off, leaving behind only the denser carbon-strut skeleton,” said Shuichiro Hayashi. “Simultaneously, the laser pulses create small ripples on the surface of the struts.”

The result is a unique, centimeter-scale, porous material with micrometer-sized struts and nanometer-scale, self-orienting surface ripples—all produced without the use of volatile chemicals and possible structural damage.

“Through our use of a three-dimensionally macro-porous material, we revealed an unexplored area of interest for the physics community, particularly in the context of light-matter interactions,” said Craig Arnold. “This work offers an adaptable method to functionalize emerging 3D materials, enhancing their properties and expanding their potential applications.”

Source: “Three-dimensional carbon fiber networks with self-orienting nano-textures enabled by femtosecond laser processing,” by Shuichiro Hayashi, Amelia Sanchirico, Ankit Das, and Craig B. Arnold, Applied Physics Letters (2025). This article can be accessed at https://doi.org/10.1063/5.0231407 .