Laser processes promise better artificial joints, arterial stents

Researchers at Purdue’s Center for Laser-Based Manufacturing are developing technologies that use lasers to create arterial stents and longer-lasting medical implants that could be manufactured 10 times faster and more cost efficiently than is now possible.

Shaoyi Wen and Andrew HechtNew technologies will be needed to meet the huge global market for artificial hips and knees, says Yung Shin, a professor of mechanical engineering and director of the center.

One of the researchers’ techniques works by depositing layers of a powdered mixture of metal and ceramic materials, melting the powder with a laser and then immediately solidifying each layer to form parts. Because the technique enables parts to be formed one layer at a time, it is ideal for coating titanium implants with ceramic materials that mimic the characteristics of natural bone, Shin says.

The laser deposition process enables researchers to make parts with complex shapes that are customized for the patient. Medical imaging scans could just be sent directly to the laboratory, where the laser deposition would create the part from the images, according to Shin. “Instead of taking 30 days like it does now because you have to make a mold first, we could do it in three days. You reduce both the cost and production time,” he says.

The researchers also are developing a technique that uses an ultra short pulse laser to create arterial stents, which are metal scaffolds inserted into arteries to keep them open after surgeries to treat clogs. Because the pulses are so fleeting, the laser does not cause heat damage to the foil-thin stainless steel and titanium material used to make the stents. The laser removes material in precise patterns in a process called “cold ablation,” which turns solids into a plasma. The patterns enable the stents to expand properly after being inserted into a blood vessel.