Advanced laser ablation techniques for precision material removal

Plasmonic Laser Nano-Ablation (PLN) uses nanoparticles to focus ultrashort laser pulses, enabling precise vaporization of sub-cellular structures without heating, useful for material removal in biological applications like cancer cell removal and gene knockout.

Background

Precision femtosecond laser microsurgery (FLMS) is a technique that utilizes tightly focused near-infrared femtosecond laser pulses to manipulate subcellular structures with submicron resolution. This method requires expensive high numerical aperture lenses to achieve the necessary focus, and the diffraction limit restricts the operational resolution to about half a micron. Additionally, current techniques often use metal particles to destroy tissue through heating effects, which can lead to significant temperature increases and potential damage to surrounding healthy tissue. This photothermal process, which can raise tissue temperatures by more than 50°C, poses a risk of collateral damage. The need for precise targeting and the limitations imposed by light diffraction present significant challenges in achieving high-resolution, non-thermal ablation at the nanoscale. Existing methods also require high laser fluence, which further complicates the procedure and increases the likelihood of unintended thermal effects.

Technology description

Plasmonic Laser Nano-Ablation (PLN) is an advanced femtosecond laser nano-ablation technique that utilizes the surface-enhanced plasmonic scattering of ultrashort laser pulses by nanoparticles to vaporize sub-cellular structures in attoliter volumes. The technology employs nanoparticles as “nano-lenses” to confine laser light to the near-field of the particles, enabling the precise photodisruption of structures only nanometers away. This method eliminates the necessity for a tightly focused beam while achieving nanoscale ablation resolution. The enhanced scattering around the nanoparticles significantly reduces the required laser fluence. The process involves positioning a nanoparticle near a material's surface, irradiating it with a laser tuned to its plasmonic frequency, and using the near-field effect to photodamage the material. This approach avoids heating for nanodisruption, making it suitable for precise material removal in various applications, including cancer cell removal and gene knockout.

What differentiates PLN from other nano-ablation techniques is its ability to achieve high precision without the need for extensive heating, which minimizes collateral damage to surrounding structures. The technique’s reliance on nanoparticles to enhance the local electromagnetic field allows for ablation at significantly lower laser fluences compared to traditional methods. This reduces the mechanical and thermal effects on adjacent tissues, making the process highly selective and efficient. Additionally, the use of femtosecond laser pulses ensures rapid energy deposition, further enhancing precision and reducing thermal diffusion. The capability to perform nanoscale photodamage opens up a wide range of applications, from biomedical procedures to nanolithography and nanomachining, making PLN a versatile and powerful tool in both scientific research and medical treatments.

Benefits

Enables nanoscale ablation resolution without the need for a tightly focused beam
Reduces required laser fluence due to enhanced scattering around nanoparticles
Avoids heating for nanodisruption, minimizing damage to surrounding structures
Can be used for precise material removal in biological applications such as cancer cell removal and gene knockout
Allows simultaneous imaging and selective material removal
Provides high throughput photomanipulation for large-scale material removal
Utilizes low numerical aperture lenses, reducing equipment costs
Applicable to a wide range of materials, including biological tissues, silicon, and glass
Effective deep within tissue structures using near-infrared light