Intraocular Lens Bond Separation via Ultrasonic Resonance
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Solution Overview
Problem
The existing methods for manufacturing intraocular lenses face challenges in efficiently separating the lenses from injection molded mold halves without damaging the lenses, particularly due to the formation of bonds between the lens material and the mold.
Innovation Solution
A method and assembly that involves mechanically engaging the spill ring material to remove it from the mold half, subjecting the mold/lens-assembly to an oscillating mechanical load to break the bonds between the intraocular lens and the mold half, and applying a static mechanical push force to separate the lens from the mold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If frictional heat and vibration are used to separate contact lenses from mold halves, then the contact lens can be separated from the mold, but the optical quality of the contact lens deteriorates due to deformation and heat
Solution Approach 1:
The patent applies mechanical vibration through a piezoelectric actuator that generates ultrasonic vibrations at a specific frequency (20-100 kHz) to break the bonds between the intraocular lens and mold half. This vibration-based separation method avoids the need for frictional heating and excessive mechanical force that would deform or damage the lens, thereby maintaining optical quality while achieving effective separation.
Solution Approach 2:
The patent changes the separation mechanism from thermal-friction-based (contact lenses) to vibration-based (intraocular lenses). By adjusting the frequency and amplitude parameters of the ultrasonic vibration to match the resonance characteristics of the mold-lens assembly, the system achieves bond breaking without causing deformation or heat damage to the delicate intraocular lens structure.
2Productivity
If strong mechanical force is applied to break bonds between intraocular lens and mold half, then separation is achieved, but the intraocular lens may be damaged
Solution Approach 1:
The patent uses ultrasonic vibration to break bonds through resonant frequency excitation rather than direct mechanical force. The piezoelectric actuator generates high-frequency oscillations that cause the bonds to fail through cumulative stress, allowing separation with minimal peak force applied to the lens, thus maintaining lens integrity while achieving efficient separation.
Solution Approach 2:
The patent introduces an intermediary mechanism (piezoelectric actuator generating ultrasonic vibrations) between the separation force and the lens-mold bond. This intermediary converts electrical energy to mechanical vibration, enabling bond breaking through resonant oscillation rather than direct mechanical impact, thereby protecting the lens from damage while maintaining separation efficiency.
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 effectively separates intraocular lenses from mold halves while maintaining the optical quality of the lenses, as evidenced by a modulation transfer function (MTF) of at least 0.54 at 50 c/mm in a Cornea Eye model, which is higher than previous methods.
Implementation Method 1
the oscillating mechanical load having an oscillation frequency which is in a range that excites the mold/lens-assembly to break the bonds between the intraocular lens and the mold half
Implementation Method 2
exerting a static mechanical push force on the bottom side of the mold half to at least partly separate the intraocular lens from the mold half
Data Source
AI summary
A method and assembly for removing an intraocular lens from an injection molded mold half. With the method and the assembly, first spill ring material is removed from the mold half. Subsequently, the mold/lens-assembly is subjected to an oscillating mechanical load without substantial deformation of at least a part of the mold half that is in direct contact with the lens body. The oscillating mechanical load has an oscillation frequency which is in a range that excites the mold/lens-assembly to break bonds between the intraocular lens and the mold half. After that, a static mechanical push force is exerted on the bottom side of the mold half to at least partly separate the intraocular lens from the mold half.