Microfluidic Jet Ejection Chamber Surface Patterning for Stable Delivery
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Solution Overview
Problem
Conventional microfluidic jet injectors face limitations in controlling injection parameters such as volume and depth, and suffer from fluidic instabilities that lead to reduced jet penetration power, reproducibility, and splash-back, making them less effective for delivering drugs into viscoelastic materials like skin.
Innovation Solution
A microfluidic device with a hosting chamber featuring a heterogeneous surface chemistry and patterned patches of different surface materials, including hydrophobic and hydrophilic regions, to control the meniscus shape and stabilize the jet ejection process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional microfluidic jet injectors are used, then the device structure is simple, but the jet stability and reproducibility are poor due to fluidic instabilities
Solution Approach 1:
The chamber wall is equipped with patches of different surface materials (hydrophobic and hydrophilic) at specific locations to control the meniscus shape and jet trajectory. This local differentiation of surface properties stabilizes the jet ejection process without requiring complete redesign of the entire device structure.
Solution Approach 2:
The heterogeneous surface chemistry pattern is pre-configured on the chamber wall to anticipate and control the meniscus formation and jet ejection behavior. This preliminary structural arrangement ensures stable jet formation from the outset, preventing fluidic instabilities before they occur.
2Manufacturing precision
If conventional jet injectors are used, then the device is easy to manufacture, but the control over injection parameters such as volume and depth is limited
Solution Approach 1:
Specific patches of different surface materials are placed at predetermined locations on the chamber wall to control meniscus shape and jet trajectory. This localized functional differentiation enables precise control over injection parameters while maintaining a relatively simple overall device structure that remains manufacturable.
Solution Approach 2:
The surface chemistry properties of the chamber wall are modified by incorporating patches with different hydrophobicity/hydrophilicity characteristics. This changes the interfacial parameters that govern meniscus formation and jet ejection, enabling precise control over injection volume and depth without fundamentally altering the manufacturing process.
3Object-affected harmful factors
If conventional jet injectors are used, then the device structure is simple, but splash-back and contamination occur due to reduced jet penetration power
Solution Approach 1:
Patches of different surface materials are strategically positioned on the chamber wall to control the meniscus shape and jet trajectory. This ensures the jet maintains sufficient penetration power through viscoelastic materials, preventing splash-back and contamination at the injection site without requiring complex additional containment structures.
Solution Approach 2:
The heterogeneous surface chemistry pattern is used to actively control and direct the jet flow in a way that converts potential harmful splash-back into controlled penetration. By manipulating the meniscus shape through surface material patches, the jet is directed precisely where needed, transforming a harmful effect into a controlled beneficial outcome.
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 device achieves improved jet stability and reproducibility by controlling the meniscus shape and trajectory, ensuring precise delivery of liquids into viscoelastic materials with reduced splash-back and contamination.
Implementation Method 1
the chamber wall comprises a pattern of a first surface material and a second surface material, wherein the first surface material has a first equilibrium contact angle θ1 for the liquid, and the second surface material has a second equilibrium contact angle θ2 for the liquid
Implementation Method 2
the first surface material has a first equilibrium contact angle θ1>90° for the liquid, and the second surface material has a second equilibrium contact angle θ2 for the liquid
Implementation Method 3
a laser-based heating system configured to provide laser radiation to the liquid in the hosting chamber
Implementation Method 4
generating a bubble inside the nozzle by absorbing a pulse of the pulsed radiation in a first portion of the fluid, thereby vaporizing the fluid into the bubble
Implementation Method 5
pushing a second portion of the fluid out of an opening at an extremity of the nozzle by an effect of an expansion of the bubble
Data Source
AI summary
The invention provides a microfluidic device (1) for jet ejection, wherein the microfluidic device (1) comprises a hosting chamber (100) defined by a chamber wall (110), wherein the hosting chamber (100) is configured to host a liquid (10), wherein along a device axis of elongation (AD) the hosting chamber (100) has a chamber length (LC) defined by a first chamber end (101) and a second chamber end (102), wherein the first chamber end (101) comprises a first chamber opening (1011) for jet ejection from the hosting chamber (100); wherein the chamber wall (110) comprises a pattern (300) of a first surface material (111) and a second surface material (112), wherein the first surface material (111) has an equilibrium contact angle θ1>90° for the liquid (10), and wherein the second surface material (112) has an equilibrium contact angle θ2 for the liquid (10), wherein θ1−θ2≥20°; wherein the pattern (300) comprises a patch (200), wherein the patch has a patch boundary (205), and wherein (a) the patch (200) comprises one of the first surface material (111) and the second surface material (112), and wherein (b) at least 50% of the patch boundary (205) contacts the other of the first surface material (111) and the second surface material (112); wherein the chamber wall (110) has a wall surface area (SW), wherein the patch (200) has a patch surface area (SP), wherein 10−4≤SP/SW≤2*10−1.