Microfluidic Die on Rigid Substrate for Vertical Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal inkjet technologies face challenges in efficiently ejecting fluids vertically without clogging, particularly when using scented oils or other fluids, due to the complexity and cost of implementing separate electrical contact planes for the print head and power supply, and the issue of fluid dripping back onto the nozzles.
Innovation Solution
A microfluidic delivery system with a rigid substrate and a planar support that allows vertical ejection of fluid from a thermal microfluidic die, featuring an inert liner to protect the substrate and separate electrical contacts in the same plane, reducing manufacturing complexity and preventing nozzle clogging by vaporizing the fluid to minimize drips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the print head is spaced from electrical contact pads to allow vertical ejection, then fluid ejection capability is improved, but manufacturing cost increases due to multi-plane construction
Solution Approach 1:
The patent combines the electrical contact pads and print head onto the same plane by using a flexible circuit board that routes electrical connections horizontally across the substrate. This merging eliminates the need for multi-plane construction while maintaining vertical ejection capability, thereby reducing manufacturing complexity and cost.
Solution Approach 2:
The patent resolves the spatial conflict by transitioning from a vertical stacking arrangement (multi-plane) to a horizontal routing arrangement (same plane). The flexible circuit board allows electrical traces to extend laterally across the substrate, placing both contact pads and print head features on the same z-level, thus eliminating the need for costly multi-layer construction.
2Productivity
If fluid is ejected vertically from the die, then ejection efficiency is improved, but nozzle clogging increases due to fluid dripping back onto the nozzles
Solution Approach 1:
The patent modifies the physical and chemical parameters of the fluid system by introducing surfactants or modifying fluid composition to control surface tension and viscosity. These parameter changes prevent fluid from dripping back onto the nozzles after vertical ejection, thereby maintaining nozzle integrity and preventing clogging while preserving ejection efficiency.
Solution Approach 2:
The patent introduces an intermediary mechanism such as a vapor barrier layer or modified nozzle surface coating that prevents direct contact between ejected fluid and the nozzle exit. This intermediary protects the nozzle from fluid accumulation and clogging while allowing efficient vertical ejection to continue.
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 system enables cost-effective and reliable vertical ejection of fluids, such as scented oils, with reduced nozzle clogging and extended system lifespan, using common materials like FR4 boards protected by inert liners, while maintaining easy manufacturing and efficient fluid delivery.
Implementation Method 1
the system is configured to vaporize the fluid sufficiently that little or no fluid drips back down onto the die
Data Source
AI summary
The present disclosure is directed to a system that is configured to eject fluid vertically away from a thermal microfluidic die for use with scented oils or other fluids. The die is coupled to a rigid planar support board that separates the die from a reservoir of the fluid. The support board includes an opening that is lined with an inert liner that protects an interior surface of the support board from the fluid. The support board includes contact to an external power supply and contacts to the die on a first surface. The die is coupled to this first surface such that the second surface remains free of electrical connections.