Thin-skinned is no insult to realistic prosthetics

Technicians at A Step Ahead in Hicksville are now impregnating a silicone leg with fire-retardant compounds for an amputee firefighter.

"We're going to really trick it out for him," said Erik Schaffer, founder and president of A Step Ahead. "It's going to look so hot."

The skin that A Step Ahead fits over high-tech prosthetics is made of the company's proprietary form of silicone. It's 1 millimeter to 1.5 millimeter thick and has the warmth and near-feel of human skin.

Human skin varies in thickness depending on the part of the body it's covering, according to the Merck Manual. It ranges from 0.5 millimeters on the eyelids to 4 millimeters or more on the palms of the hands and soles of the feet.

At Schaffer's prosthetics factory, artisans color the silicone on both sides to match each patient's skin tone. Fingernails and toenails, made of acrylic and added to hands and feet, complete a realistic look.

"Our skins are as thin as possible," Schaffer said, but strong and flexible enough, he added, to create feet for women that can accommodate a 4-inch high heel or an open-toed shoe.

The use of artificial skin is not unique to Schaffer's practice. Touch Bionics, makers of the i-Limb hand, a high-tech prosthetic, makes a product called Livingskin. Other Long Island prosthetists and the Veterans Affairs Medical Center in Manhattan fashion silicone or latex skins onto robotic legs and other replacement limbs.

The development of flexible, thin silicone skin has complemented parallel advances in highly articulated artificial limbs.

"If it's too thick, it would not allow the i-Limb to function," said Lisa Prasad, spokeswoman for Touch Bionics. A thicker material, she said, might bunch when a wearer tried to pick up an object, impeding the hand's ability to grip.