CS Colloquium, co-sponsored w/Biomedical Engineering - Steven L. Jacques, Tufts Univ.

Event time: 
Friday, October 27, 2017 - 4:00pm
Location: 
AKW 000 See map
51 Prospect Street
New Haven, CT 06511
Event description: 

CS Colloquium, co-sponsored with Biomedical Engineering

Steven L. Jacques
Biomedical Engineering
Tufts University

Title: The optics of skin: why skin looks pink instead of orange

Host: Alex Doronin

Abstract:

The skin is an optically turbid medium with embedded absorbers (blood, melanin, water) and scatterers (collagen, lipid membranes). The scattering greatly affects the observed color of the skin. A homogeneous mixture of scatterers and blood will yield an orange color, since absorption by blood scales as blue > green > red. But the architecture of the skin has a superficial layer of relatively low blood content: the epidermis and superficial papillary dermis. Hence, blue light can reflect from this superficial layer before seeing any blood while green and red light penetrate more deeply and see the deeper blood. This moves the skin color from orange to pink. Of course, melanin offers an additional absorption filter that strongly attenuates blue light, but subsurface melanin yields the blue coloring of Nevus of Ota. IN SUMMARY, skin architecture plays a key role in the appearance of skin color.