Chapter 6: Crown Sonics

This semiconductor nature allows melanin to absorb a broad spectrum of electromagnetic radiation, from UV to near-infrared light. The absorbed energy is then efficiently converted into other forms, primarily heat, through a process known as photon-phonon coupling. A phonon is a quantum of vibrational energy, and this conversion of light (photons) to vibrational energy (phonons) is a key aspect of melanin’s protective function. By dissipating absorbed energy as heat, melanin shields the surrounding tissues from potentially damaging radiation.

The photo-acoustic properties of melanin are a direct consequence of this energy conversion. The photo-acoustic effect describes the generation of sound waves (acoustic energy) resulting from the absorption of light. When melanin absorbs light, the rapid heating and subsequent thermal expansion of the material generates a pressure wave, which is essentially a sound wave. This phenomenon is so pronounced that melanin is being explored as a contrast agent in photo-acoustic imaging, a biomedical imaging modality that combines light and sound to create detailed images of tissues. In the context of hair, this means that melanin is constantly converting light energy into both heat and sound, acting as a transducer at the nanoscale.

Furthermore, melanin is described as a “formidable energy absorber of UV-visible-NIR photons and US phonons”. This indicates that melanin can directly absorb acoustic energy in the form of ultrasound (US) phonons. This ability to absorb sound waves, coupled with its efficient energy dissipation mechanisms, makes melanin an excellent acoustic protector. It can dampen and absorb incoming acoustic energy, shielding the hair follicle and surrounding cells from potential damage caused by high-intensity sound waves.

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The concept of melanin as an “acoustic amplifier” is more nuanced. It does not amplify sound in the conventional sense of making it louder. Instead, the amplification refers to the transduction of other energy forms, like light, into acoustic energy.

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Melanin | Light to Sound Energy

The synergistic interplay between melanin and other materials, such as metals, can significantly enhance this photo-acoustic response. This suggests that the specific environment and composition of the hair follicle can influence the efficiency of this energy conversion process. The unique coiled structure of afro-textured hair, combined with its high melanin content, creates a system that is highly effective at interacting with and transducing various forms of energy.

In summary, melanin’s role as a hidden amplifier and protector is rooted in its fundamental properties as a semiconductor biopolymer. Its ability to absorb a wide range of energy, from light to sound, and efficiently convert it into heat and acoustic vibrations, allows it to both protect the body from harmful radiation and act as a sophisticated energy transducer. The high concentration of melanin in afro-textured hair, therefore, bestows upon it a unique and powerful set of photo-acoustic and protective capabilities.

Excerpt from Crown of Thorns Pg  80-81