Fast Fluidic Assembly for Nanoscale Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for printing microscale and nanoscale features in electronics manufacturing are limited by low throughput, diffusion-controlled processes, and require conductive substrates, making it difficult to achieve resolutions comparable to conventional silicon-based fabrication.
Innovation Solution
A high-throughput directed assembly method using dip-coating without diffusion effects, relying on alternating hydrophobic and hydrophilic surfaces, which allows for faster withdrawal speeds and selective binding of nanoelements to hydrophilic regions, enabling printing on both rigid and flexible substrates without applied electrical potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dip-coating is used with dilute suspensions in a diffusion-controlled process, then nanomaterials can be selectively assembled, but the withdrawal speed must be low which reduces throughput
Solution Approach 1:
The patent replaces the diffusion-controlled mechanism with an electric field-driven mechanism. The electric field actively propels nanomaterials toward the substrate, substituting the passive Brownian motion with an active directed transport mechanism, thereby enabling high withdrawal speeds while maintaining assembly precision
Solution Approach 2:
The patent changes the controlling parameter from diffusion coefficient to electric field strength. By applying an external electric field, the transport mechanism transitions from passive diffusion to active electrophoretic/dielectrophoretic motion, allowing withdrawal speeds to increase by orders of magnitude while preserving selective assembly capability
2Productivity
If electric field is applied to increase particle concentration and reduce diffusion time, then printing speed increases, but conductive substrate is required which limits substrate choice
Solution Approach 1:
The patent introduces an intermediary electric field generation mechanism that does not require the substrate itself to be conductive. The field can be generated by electrodes on the opposing side of a insulating layer or by field emission tips, allowing the substrate to remain electrically isolated while still benefiting from the electric field-driven assembly
Solution Approach 2:
The patent separates the electric field generation function from the substrate. The field-generating components (electrodes, emitters) are positioned independently from the substrate, allowing the substrate to be any material while the field is applied through intermediate structures
3Ease of manufacture
If conventional printing processes are used, then manufacturing cost is reduced, but the minimum feature size is limited to about 10 μm which is insufficient for modern electronics
Solution Approach 1:
The patent uses liquid suspensions containing nanomaterials as the printing medium, replacing conventional paste or ink formulations. The liquid vehicle allows for better dispersion and control of nanoscale particles, enabling feature sizes an order of magnitude smaller than conventional processes while maintaining cost-effective solution processing
Solution Approach 2:
The patent changes the material state from conventional paste/ink to liquid suspension with controlled particle concentration and size distribution. This parameter change enables the liquid to flow into and fill nanoscale features capillary-like, achieving sub-10 μm resolution while maintaining the simplicity and low cost of liquid-based printing
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 method enables high-speed printing of microscale and nanoscale features with controlled thickness and width, overcoming previous limitations by operating in the draining regime, allowing for the use of various materials and substrates, and achieving resolutions down to sub-100 nm scale.
Implementation Method 1
withdrawing the substrate out of the suspension and into air or gas above the suspension at a speed that allows evaporation of the liquid but not draining of the suspension
Implementation Method 2
nanoelements from the suspension bind selectively to the hydrophilic regions to form said nanoscale or microscale pattern of nanoelements
Data Source
AI summary
A scalable printing process capable of printing microscale and nanoscale features for additively manufacturing electronics is provided. This fast, directed assembly-based approach selectively prints microscale and nanoscale features on both rigid and flexible substrates. The printing speed is much faster than state-of-the-art inkjet and flexographic printing, and the resolution is two orders of magnitude higher, with minimum feature size of 100 nm. Feature patterns can be printed over large areas and require no special limitations on the assembled materials. Hydrophilic/hydrophobic patterns are used to direct deposition of nanomaterials to specific regions or to selectively assemble polymer blends to desired sites in a one-step process with high specificity and selectively. The selective deposition can be based on electrostatic forces, hydrogen bonding, or hydrophobic interactions. The methods and nanoscale patterned substrates can be used with polyelectrolytes, conductive polymers, colloids, and nanoparticles for application in electronics, sensors, energy, medical devices, and structural materials.