Microfluidic Platform Constriction for Microsphere Trapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microsphere positioning methods for optical biosensing are challenging due to the small size and precision requirements, making it difficult to handle and position microspheres effectively, and irreversible bonding to substrates complicates handling and alignment.
Innovation Solution
A microfluidic platform with a constriction that traps microspheres in a precise location within a channel, allowing for easy handling and positioning, eliminating the need for optical alignment and enabling the use of low-cost, disposable microspheres, and allowing for trap-and-release functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If microspheres are permanently bonded to an optical substrate or fiber, then it is easier to handle and position the microsphere, but the arrangement is irreversible and complicates handling and alignment
Solution Approach 1:
The patent employs a microfluidic channel system that dynamically positions microspheres through controlled fluid flow. The channel geometry creates a trapping region where microspheres are passively held in place during optical measurement, then can be released and removed through continued flow. This dynamic positioning eliminates the need for permanent bonding while maintaining ease of handling and positioning.
2Manufacturing precision
If microspheres are placed on stems and handled with micro-positioners, then positioning is possible, but it is difficult to handle and position a microsphere in a desired manner due to small size and precision requirements
Solution Approach 1:
The patent uses a microfluidic channel system where fluid flow dynamically positions microspheres. The channel geometry creates a trapping region that passively holds microspheres in precise locations through hydrodynamic forces, eliminating the need for complex mechanical micro-positioners. This approach achieves high placement precision while greatly simplifying handling operations.
Solution Approach 2:
The microfluidic system enables self-positioning of microspheres through controlled fluid flow. The channel geometry and flow conditions automatically guide microspheres to the desired trapping region without requiring external positioning mechanisms. The system serves itself by using the fluid flow to both deliver and position the microspheres, eliminating the need for separate positioning operations.
3Ease of operation
If irreversible bonding is used to secure microspheres, then handling is simplified, but the arrangement cannot be reversed and prevents reuse
Solution Approach 1:
The microfluidic channel system provides dynamic positioning that can be reversed. Microspheres are held in place during measurement through controlled fluid flow, then can be released and removed through continued flow. This reversibility enables the same microsphere to be reused in different experimental configurations, maintaining ease of handling while enabling adaptability and reusability.
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
The microfluidic platform securely positions microspheres for optical biosensing, maintaining high Q-factor resonances and enabling sensitive biomolecular detection with improved ease of use and reduced costs, while allowing for efficient removal and reuse of microspheres.
Implementation Method 1
A microfluidic channel through which a fluid that contains the microsphere can flow. The channel includes a constriction that can be used to trap the microsphere
Implementation Method 2
Optical resonator biosensors use optical resonators that exhibit sharp, i.e., high Q, optical resonances from their whispering gallery modes (WGM). Those resonances can be used for highly sensitive biodetection as they shift when small amounts of biomolecules attach to the resonator surface.
Implementation Method 3
Optical biosensors are used to sense the local increase of refractive index that occurs near the surface as a result of the accumulation of the molecules of interest
Data Source
AI summary
In one embodiment, a microfluidic platform for optical biosensing, the platform including an optical substrate, a layer provided on the substrate, and a channel formed within the layer and defined by the layer and the substrate through which fluid can flow, the channel including a channel constriction that gradually narrows along a length of the channel to a point at which the channel is physically sized and configured to trap a microsphere suspended in the fluid when the fluid flows through the channel so that the microsphere cannot pass the channel constriction.