Stents No Longer Too Hot to Handle

Author: 
Bob Michaels
Stents are typically manufactured using thermal laser technology. Committed to the idea that stents should chill, Raydiance Inc. has developed Smart Light MD, a femtosecond laser platform that enables athermal ablation. This technology, according to the company, benefits stent manufacturing and medical microdevice applications such as drug-delivery systems, guidewires, valves, and needles.
Raydiance's Smart Light MD laser platform enables athermal ablation, ending the need for rework.

Smart Light is a computer-controlled system based on a fiber-optic architecture. “To appreciate what that means, it is helpful to understand the broad landscape of lasers,” says Adam Tanous, Raydiance’s director of marketing. “Lasers can be divided into continuous wave (CW) systems, which emit a beam continuously, and pulse systems, which deliver energy in discrete pulses. The pulsed laser world breaks down into longer-pulse systems—those with pulse durations in the nanosecond and picosecond regime—and ultrafast lasers—those with subpicosecond-pulse durations typically in the 600- to 900-fs range.”

CW lasers ablate by localized heating of the target lattice followed by phase change or combustion, Tanous explains. Ultrafast lasers, in contrast, emit high-energy pulses in rapid bursts, creating a high electric field that initiates multiphoton ionization, stripping electrons from the target atoms. This leads to plasma formation, followed by electrostatic ejection of the target ions.

Femtosecond lasers process materials faster than heat can diffuse into the target substrate. While longer-pulse lasers can initiate ionization, they linger too long, allowing heat from the laser to diffuse into the part, creating such thermal damage as melt areas, recast, or microstructure changes. Even subtle effects can compromise device integrity, Tanous notes. In addition, rework can require chemical etching, which can limit the feature sizes of the devices.

Enjoying a partnership with Raydiance, Norman Noble Inc. has integrated the Smart Light into its existing proprietary laser machining system, dubbed Noble UltraLight. As the sole contract manufacturing source incorporating Raydiance’s laser technology into its own systems, Norman Noble uses it to manufacture nitinol neurovascular stents, nitinol heart valves, and bioabsorbable cardiovascular stents.

“We can machine all types of polymers and bioabsorbable materials using our Noble UltraLight systems,” says Brian Hrouda, the company’s director of sales and marketing. “We can also cut all types of metals. In fact, we have not found a material that these systems cannot cut. And they do so without generating thermal damage to the material, a feat that was once unimaginable to most design engineers.”

Raydiance Inc.
Petaluma, CA
www.raydiance-inc.com

Norman Noble Inc.
Highland Heights, OH
www.nnoble.com