Feathers help birds fly, fur keeps mammals warm, and whiskers help facilitate sensing. While these functions are quite specific, the form of these structures (feathers, fur, and whiskers) are all composed of keratin. We are taking inspiration from one particular animal structure, whiskers, to understand how this keratin building block can help facilitate sensing in animals. A wide range of terrestrial and aquatic mammal species use these whiskers as tactile sensory organs emerging from the skin for environmental monitoring tasks such as detecting unseen obstacles or perceiving wind direction. Most research focuses on understanding the complex whisker structures' geometry or their neuromechanics, studying the mechanoreceptors in the skin connected to the elongated whisker, which is assumed to be homogeneous.

We seek to understand how variations in stiffness, porosity, and geometry can impact the transmission of vibrations through biological composites such as whiskers, body hairs, skin, and feathers. We are working to combine material science, medical imaging, and biophysics with mechanical engineering modeling to determine how materials play a role in animal touch. Interestingly, the haptic interactions of these keratin-based structures bear significant resemblance to tool-mediated surface interactions by humans, as haptic vibrations travel from the contact through the whisker or the stylus to sensitive skin tissue in both cases. Thus, our experience with human touch can sometimes facilitate insights about animal touch.

This research project involves collaborations with Michael Brecht (Humboldt University of Berlin), Lena V. Kaufmann (Humboldt University of Berlin), Felicitas Predel (Max Planck Institute for Solid State Research), Vesna Srot (Max Planck Institute for Solid State Research), and Peter A. van Aken (Max Planck Institute for Solid State Research).