Inflatable Balloon Surface Etching Without Polymer Heat Damage
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Solution Overview
Problem
Inflatable medical devices face challenges such as overheating during laser modification, which disorients polymer chains, reducing the strength and consistency of the device, and issues with uneven wall thickness and friction, affecting their performance in anatomical procedures.
Innovation Solution
The use of low heat ultrashort laser pulses to modify the surface of inflatable devices, such as medical balloons, without significant thermal effects, allowing for customized features like recessions and improved bonding while maintaining the polymer network morphology, thus preserving elasticity and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional laser ablation is used to modify the surface of inflatable devices, then material removal and surface modification are achieved, but significant heating occurs that disorients polymer chains and reduces device strength
Solution Approach 1:
The patent applies periodic pulsed laser action instead of continuous laser exposure. The laser delivers energy in short, periodic pulses that allow thermal diffusion to occur between pulses, preventing heat accumulation and polymer chain disorientation while still achieving effective surface modification and material removal.
Solution Approach 2:
The patent changes the thermal parameters of laser processing by controlling pulse duration, duty cycle, and inter-pulse intervals. These parameter adjustments ensure that the thermal diffusion length remains limited, preventing heat from reaching depths that would cause polymer chain disorientation, thereby maintaining device strength while achieving surface modification.
2Manufacturing precision
If laser ablation is used to create surface features, then customized surface features are achieved, but thermal effects alter the polymer network morphology surrounding the modification
Solution Approach 1:
Periodic pulsed laser delivery allows the polymer matrix to thermally relax between pulses, preventing cumulative thermal effects that would alter the polymer network morphology. The periodic timing is specifically designed to match thermal diffusion timescales, enabling surface feature creation while preserving the surrounding polymer structure.
Solution Approach 2:
The patent achieves local surface modification with high precision while maintaining the bulk polymer network integrity. The laser parameters are tuned so that thermal effects are confined to the immediate surface region where modification is desired, leaving the surrounding polymer network morphology unchanged.
3Productivity
If high energy laser is used for material removal, then efficient ablation is achieved, but excessive heat damages the surrounding polymer structure
Solution Approach 1:
The periodic pulsed laser regime maintains high material removal efficiency by delivering energy in concentrated pulses that achieve effective ablation during each pulse duration, while the intervals between pulses allow heat to dissipate before reaching damaging levels in the surrounding polymer.
Solution Approach 2:
The laser pulses are designed to deliver sufficient energy for effective material removal within the short pulse duration, then skip (interrupt) before thermal damage can propagate. This rushing through the ablation process quickly and then pausing prevents cumulative thermal damage while maintaining productivity.
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 approach enables inflatable devices with enhanced friction, predictable burst pressure, improved bonding to external devices, and customized features that facilitate easier delivery and deployment, reducing tissue damage and improving procedural accuracy.
Implementation Method 1
EP0783897 A2 describes laser ablation on a dilatation balloon to remove material thereon
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A~2B
AI summary
Inflatable devices are disclosed including a surface which has a network of polymer chains and is configured to be inflatable into a therapeutically or diagnostically useful shape, and at least one ultrashort laser pulse-formed modification in the surface. The network can, for example, include a network morphology that is substantially unchanged by modification with the ultrashort pulse laser. Ultrashort laser pulses can be laser pulses equal to or less than 1000 picoseconds in duration. Advantageously, the etching process uses a relatively low-heat laser to avoid significant heating of surrounding polymers while modifying the surface (and other structures) of the device. The process is configured so that the polymer chain morphology adjacent the modification is substantially unaffected by the low-heat laser. The resulting inflatable device has customized surface features while still retaining substantially homogenous polymer network morphology. This preserves the elasticity, especially the surface elasticity, of the inflatable device.