Flexible Substrate Pattern Transfer Using a Hydrophobic Membrane Mask
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Solution Overview
Problem
Existing methods for fabricating electronic devices on flexible substrates using materials like graphene oxide are costly, time-consuming, require clean room facilities, and lack versatility, especially in creating simple devices like transistors or capacitors.
Innovation Solution
A method involving printing a hydrophobic mask on a porous membrane, filtering an electronic material suspension through the non-printed regions, and transferring the patterned material to a flexible substrate using pressure, without acetone, leveraging van der Waals interactions for direct contact and pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If spin coating, self-assembly, vacuum filtration or solvent exchange methods are used to fabricate electronic devices, then uniform and controllable deposition of electronic materials can be achieved, but the fabrication period becomes long and the cost increases
Solution Approach 1:
The patent extracts and eliminates the acetone dissolvent step from the traditional fabrication process. By using a hydrophobic mask that directly repels water-based electronic material suspensions, the method removes the time-consuming solvent exchange and drying steps, achieving uniform deposition without the long fabrication periods associated with traditional methods
Solution Approach 2:
The patent segments the fabrication process into distinct functional zones using a hydrophobic mask with patterned regions. The mask divides the substrate surface into hydrophobic (patterned) and hydrophilic (non-patterned) regions, allowing selective deposition of electronic materials only in desired areas, thereby achieving uniform deposition in a simplified, faster process
2Manufacturing precision
If spin coating, self-assembly, vacuum filtration or solvent exchange methods are used, then electronic devices can be fabricated with controlled patterns, but clean room facilities and high expertise are required
Solution Approach 1:
The patent employs a disposable hydrophobic mask that can be printed using conventional printing techniques. This mask is inexpensive and does not require clean room facilities for its application or removal. The mask performs its patterning function and is then discarded, eliminating the need for expensive clean room infrastructure and specialized expertise while maintaining precise pattern control
Solution Approach 2:
The patent replaces complex mechanical and chemical systems (spin coaters, vacuum filtration equipment, solvent exchange apparatus) with a simple hydrophobic mask-based system. The pattern control is achieved through the hydrophobic properties of the mask rather than through complex mechanical deposition equipment, significantly simplifying the manufacturing requirements
3Manufacturing precision
If acetone dissolvent is used to transfer electronic material from membrane to substrate, then complete transfer can be achieved, but the process becomes costly and environmentally harmful
Solution Approach 1:
The patent converts the hydrophobic property of the mask, which initially seems to prevent complete transfer, into a beneficial feature. The hydrophobic regions naturally repel the water-based electronic material suspension during filtration, preventing deposition in unwanted areas, while the hydrophilic regions allow complete transfer. This eliminates the need for acetone dissolvent and its associated environmental harm while maintaining precise transfer control
Solution Approach 2:
The hydrophobic mask serves as an intermediary between the electronic material suspension and the final substrate. It mediates the transfer process by using hydrophobic-hydrophilic interactions to guide material deposition, replacing the need for chemical dissolvents like acetone and eliminating harmful chemical waste while achieving complete and precise material transfer
4Adaptability or versatility
If traditional fabrication methods are used, then electronic devices can be produced, but versatility in designing simple devices like transistors or capacitors is limited
Solution Approach 1:
The patent creates a universal fabrication platform using a hydrophobic mask that can pattern any electronic device structure by simply changing the mask design. The same hydrophobic mask mechanism works for fabricating transistors, capacitors, electrodes, and other electronic components, providing versatile device design flexibility without increasing fabrication process complexity
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
Enables low-cost, efficient, and versatile fabrication of electronic devices on flexible substrates, eliminating the need for clean rooms and acetone, and allowing for industrial-scale production of sensors and biosensors with controlled transparency and conductivity.
Implementation Method 1
Vacuum filtration involves the filtration of a GO suspension through a commercial mixed nitrocellulose ester membrane (NCM) with an average pore size of 25 nm. As the suspension is filtered through the membrane, the liquid is able to pass through the pores but the GO sheets become lodged on the membrane.
Implementation Method 2
printing a hydrophobic mask on a porous membrane to form a pattern thereon... filtering an aqueous suspension of an electronic material through the non-printed region of the porous membrane
Implementation Method 3
The transfer phenomena are related to the hydrophobicity of the porous membrane and to the GO humidity, which for example makes NCM a good membrane in order to easily release the GO... leveraging van der Waals interactions for direct contact and pattern transfer
Data Source
AI summary
A method of forming an electronic device on a flexible substrate without using acetone dissolvent, including the steps of: printing a hydrophobic mask on a porous membrane to form a pattern thereon which is complementary to a desired pattern; filtering an aqueous suspension of an electronic material through the non-printed region of the porous membrane, whereby some electronic material is deposited on said non-printed region following the desired pattern; pressing the flexible substrate against the printed face of the membrane in order to transfer the patterned electronic material deposited on the porous membrane to the flexible substrate to form the electronic device thereon.