Galvo Mirror Laser Spot Control for MALDI Mass Spectrometers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mass spectrometers with ionization by matrix-assisted laser desorption (MALDI) face challenges in achieving fast positional control of laser spots due to high inertia in sample support plate movement, limiting sample utilization and spatial resolution in high-density analysis and imaging mass spectrometry.
Innovation Solution
A laser system with fast positional control using small, low-inertia galvo mirrors before beam expansion, coupled with a Kepler telescope to redirect the beam and maintain precision, allows for continuous sample support movement and uniform ablation without mechanical stress, enabling efficient analyte molecule utilization and high spatial resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the sample support plate is moved stepwise to position samples under the laser, then discrete sample locations can be analyzed, but the high inertia of the support plate prevents fast movement between samples during high repetition rate laser sequences
Solution Approach 1:
The patent replaces the mechanical movement of the sample support plate with an optical system (galvo mirrors) to achieve fast laser spot positioning. The galvo mirrors can reposition the laser spot within 100 microseconds between laser shots, enabling the system to keep up with high repetition rate lasers (10 kHz) without being limited by the inertia of the sample support plate.
2Speed
If small galvo mirrors are used for fast laser spot repositioning, then rapid positional control is achieved, but the small beam diameter limits the mirror size and requires placement before beam expansion
Solution Approach 1:
The patent introduces dynamic control of the laser beam path using galvo mirrors that can rapidly change the beam direction. The system dynamically adjusts the beam path from the laser source through the galvo mirrors to the sample, enabling fast repositioning without mechanical movement of the sample support.
Solution Approach 2:
The patent adds a new dimension to the optical path by introducing galvo mirrors that operate in the angular deflection space. Instead of moving the sample support plate in physical space, the system uses mirror rotation to deflect the laser beam to different sample locations, transforming a translational problem into an angular deflection problem.
3Area of stationary object
If the laser spot position is controlled by mirrors with large diameter near the sample, then beam coverage is improved, but the high inertia prevents repositioning within 100 microseconds
Solution Approach 1:
The patent performs preliminary beam expansion using a Kepler telescope before the laser beam reaches the galvo mirrors. This allows the use of smaller mirrors with lower inertia that can still effectively control the expanded beam, achieving both fast repositioning and adequate beam coverage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables optimal analyte molecule utilization and maintains spatial resolution in high-density analysis and imaging mass spectrometry by allowing rapid laser spot positioning and continuous sample support movement, overcoming the limitations of high inertia in existing systems.
Implementation Method 1
it contains the special telescope for expanding the beam
Implementation Method 2
A laser system with fast positional control using small, low-inertia galvo mirrors before beam expansion, coupled with a Kepler telescope to redirect the beam
Implementation Method 3
A light pulse from the laser, usually a UV laser, is used to generate a plasma cloud of sample material in which ions of the matrix and analyte molecules are produced
Implementation Method 4
generate a plasma cloud of sample material
Implementation Method 5
A voltage applied to diaphragms in the ion source accelerates the ions into a field-free flight tube
Data Source
AI summary
Mass spectrometers ionize samples by matrix-assisted laser desorption (MALDI). The samples are located on a moveable support plate, and irradiated by a pulsed laser. A fast positional control of laser spots is provided via a system of rotatable mirrors to relieve strain on a support plate motion drive. If the spot position is finely adjusted by the mirror system and follows the movement of the sample support plate, the intermittent movement of the sample support can be replaced with a continuous uniform motion. The fast positional control allows more uniform ablation of a sample area. Galvo mirrors with low inertia may be used between the beam generation and a Kepler telescope in the housing of the laser. The positional control can also provide a fully automatic adjustment of MALDI time-of-flight mass spectrometers, at least if the ion-optical elements are equipped with movement devices.