Tawfick learns from hair to develop reconfigurable, self-healing surfaces

MechSE assistant professor Sameh Tawfick won a grant from the competitive Air Force Office of Scientific Research Young Investigator Program (AFOSR YIP) for his research “Additive Manufacturing of Polymorphic Hair Material Systems for Reconfiguration and Damage Restoration."

The AFOSR YIP awarded 31 grants, to begin in 2019, to scientists and engineers at U.S. research institutions for work that shows a relevancy to future Air Force or other military applications. The program supports young researchers and increases their opportunities to address scientific challenges within the Air Force mission.

Tawfick is attempting to develop transformable surfaces that are reconfigurable and self-healing. For the Air Force, the characteristics of a surface are integral, and the ability to have an extra element of control in that respect would be game-changing. 

Tawfick has always been inspired by the versatility of hair as a material. In nature, hair serves different purposes in different environments, from keeping animals warm in the winter to reflecting UV rays on leaves. Pairing hair with the capillary forces in a liquid expands its uses even further. When a person’s hair gets wet, the hair’s texture changes. The capillary forces from the water pull the hair together, morphing it from individual strands into bundles. When the water dries, the texture returns to how it was before.

“We’re interested in novel active surface technologies and complex shape-changing textures, and hair is basically the ultimate texture seen in nature,” Tawfick said. “It’s very long, thin, and slender so it can bend, it can be twisted, and it can form different spikes. You can control this morphology like no other texture simply by wetting and drying.”

As undergraduate students in MechSE, Dongwoo Shin and Lauren Kovanko (now a graduate student in Tawfick’s lab) initially developed these research concepts and weighed their feasibility. Now, Tawfick’s group uses additive manufacturing technology to print the hair for testing. The researchers use 3D-printed hair and carbon fiber hair to form specific configurations and then insert and remove liquid. The shape the hair takes is determined by the presence of the liquid and the rate at which it is inserted.

Once the researchers understand how the hair interacts with liquids under different conditions, liquids other than water can be incorporated to fix specific textures. A polymer inserted in the place of water can form a fiber-reinforced composite texture as it dries.

Tawfick’s lab already has an additive manufacturing technology necessary to print hair and the ability to create carbon fiber hairs. He will use funds from the grant to create a new technology to install various types of hairs onto any surface.

Tawfick believes that the ability to create reconfigurable, transformable surfaces could add an additional dimension to design that changes every industry it touches.