Lasers & photonics
ones are more complex than they appear. Beneath the skin and muscle, they are living tissue, with a dense mineralised outer layer (cortical bone) and a porous interior (trabecular bone) containing marrow and microscopic channels. Together, these structures give bones their strength and their ability to repair themselves gradually when broken.
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Sometimes, though, the damage is so severe that grafts or implants are required to bridge defects and support healing. These can involve metal or ceramic materials, but surgeons often prefer autografts, bone taken from elsewhere in the patient’s body, because they integrate well with existing tissue. Even then, bone’s complex internal architecture can slow healing, especially if repair cells cannot migrate efficiently into and through the graft. One possible solution is a hydrogel developed by researchers at ETH Zurich. The hydrogel is 97% water and 3% biocompatible polymer. To solidify it, the researchers added molecules that link the polymer chains and trigger the cross-linking reaction when exposed to laser light. Developed by ETH Zurich professors Ralph Müller and Xiao-Hua Qin with former doctoral student Wanwan Qiu, the hydrogel is designed to mimic the soft, permeable scaffold that forms during early bone repair, allowing immune and repair cells to migrate into the defect. A key advance is the laser-based process used to shape it. Using two-photon laser microfabrication, the ETH Zurich team produced hydrogel structures with feature sizes down to about 500nm. The team reported writing speeds of up to 400mm/s, which ETH Zurich professor Xiao-Hua Qin described as “a new world record”.
The hydrogel technology remains at a preclinical stage, but it is one of several recent advances in laser engineering for medical device development. Once largely confined to specialist laboratories, lasers are now used to cut, drill, texture and shape a range of implants and devices, including orthopaedic and dental components, hernia-repair meshes and bioelectronic sensors. Laser technology increasingly enables patient-specific devices that can, in principle, be manufactured at scale.
Focused energy
The first laser had no immediate, obvious commercial application. Theodore Maiman made the first working laser in 1960 using a high-power flash lamp and a synthetic ruby crystal. His first paper describing the invention was rejected by Physical Review Letters; accounts suggest editors considered it insufficiently distinct from earlier maser and ruby research. By the early 2000s, laser technology had advanced to the point where manufacturers, including medical device OEMs, were using it for machining at micron-level precision. Medical device manufacturers have made particular use of ultrafast lasers, including
www.medicaldevice-developments.com
femtosecond systems. The development of today’s ultrafast laser systems owes much to chirped pulse amplification, pioneered by Gérard Mourou and Donna Strickland, who shared half of the 2018 Nobel Prize in Physics for their method of generating high- intensity, ultrashort optical pulses. Femtosecond lasers fire extremely short pulses of light, often in the 300–400 femtosecond range; one femtosecond is one quadrillionth (10-15
) of a second.
As an article in Medical Product Outsourcing explains, ultrafast laser micromachining can be performed in systems compact enough for factory or laboratory use. Such short pulses can deposit energy into a material faster than that energy can spread significantly into the surrounding area. In practical terms, this allows femtosecond lasers to ablate material with an extremely small heat- affected zone, reducing melting, deformation and other thermal damage.
“Recent advances in laser-based fabrication have significantly accelerated the development of bioelectronic devices.”
Materials Science and Engineering
This is a valuable quality when manufacturing small, delicate implants. The specifications of such devices are highly complex. At a minimum, a device may need to be biocompatible and corrosion- resistant, while manufacturers must also minimise the risk of microbial contamination and infection. Lasers can help OEMs address some of these requirements. Beyond their ability to machine an exceptionally wide range of materials, the limited heat-affected zone associated with ultrafast lasers can reduce burrs, melting and the amount of post- processing required. That has widened the variety of devices that can be machined with femtosecond systems. Examples include polymer balloon catheters, fine filter structures with struts only tens of micrometres thick, and meshes used in hernia-repair procedures. Femtosecond lasers are also used to machine small features such as delivery holes in cannulas and catheters for precise drug administration.
Light work
Different wavelengths of light have different effects depending on the material and device being processed. Infrared femtosecond lasers, for example, are used to machine stents and polymer tubing, while green-wavelength femtosecond lasers can drill holes in cannulas and catheters and modify some implant surfaces. A 2025 review in Nanomaterials summarises recent advances in laser-processed functional surfaces for medical devices, including effects on
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