Rectifying Device Charge Patterning for Micro Assembly Stiction

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Solution Overview

Problem

Micro assembly techniques face challenges in accurately moving micro objects due to stiction and in patterning micro objects, particularly with uncontrolled tribocharging and proton exchange methods leading to complications from ion screening.

Innovation Solution

The use of rectifying devices with asymmetric current-voltage response curves in micro objects, coupled with external electric or magnetic fields, to induce charge patterns and facilitate precise manipulation and positioning, minimizing stiction and improving patterning reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If electrostatic or magnetic fields are used to manipulate micro objects, then micro objects can be moved and positioned, but stiction causes significantly greater forces to be required to initiate motion compared to maintaining motion, resulting in control instabilities

Engineering Contradiction:

Improveforce required to initiate motionVSAvoidcontrol stability

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The patent applies periodic AC electric fields to continuously overcome stiction forces. By applying oscillating fields at frequencies that exceed the stiction threshold, the system maintains micro objects in a state of continuous micro-movement, preventing them from settling into static friction states. This periodic action converts the problematic static friction into manageable dynamic friction conditions.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system transitions from static DC field application to dynamic AC field application. By making the electric field time-varying and oscillating, the system adapts to the dynamic nature of stiction forces, continuously adjusting the field strength and direction to maintain control stability during micro object manipulation.

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If tribocharging or proton exchange methods are used for patterning micro objects, then charge patterns can be formed, but these methods are uncontrolled and lead to complications from ion screening

Engineering Contradiction:

Improvepatterning controlVSAvoidion screening complications

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces chemical patterning methods (tribocharging, proton exchange) with a physical field-based approach. By using AC electric fields to induce charge patterns through capacitive coupling, the system eliminates the need for chemical electrolytes and ion-based processes, thereby removing ion screening complications while maintaining patterning capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the fundamental parameter for charge patterning from chemical properties (acidity levels, ion concentration) to electrical field parameters (frequency, amplitude, waveform). By controlling the AC field parameters, the system achieves precise and repeatable charge patterns without the uncontrolled variations inherent in chemical methods.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If planar electrode arrays are permanently affixed to substrates for micro object manipulation, then micro objects can be positioned and oriented, but both intermediary and final substrates are required, increasing system complexity

Engineering Contradiction:

Improvemicro object positioning capabilityVSAvoidsubstrate requirements

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent makes the electrode array portable and reusable across different substrates. By decoupling the electrode array from permanent substrate attachment, the same electrode array can be used for both intermediary substrate manipulation and final substrate assembly operations, eliminating the need for separate specialized substrates and reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The portable electrode array acts as an intermediary tool that can temporarily interface with different substrates as needed. Rather than requiring permanent substrate-integrated electrodes, the electrode array serves as a reusable mediator that can be applied to various substrates for specific manipulation tasks, then removed and reused elsewhere.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach enables precise control over micro object movement and patterning, reducing stiction-related issues and enhancing the reliability of micro assembly processes by using rectifying devices to manage charge patterns effectively.

Implementation Method 1

a rectifying device which exhibits an asymmetric current-voltage (I-V) response curve

Methodology Applied

Scientific EffectRectification: Diode

Data Source

PatentUS10141285B2Externally induced charge patterning using rectifying devices

Publication Date: 2018.11.27 GENESEE VALLEY INNOVATIONS LLC

AI summary

A system and method form charge patterns on micro objects. The system and method employ a micro object including a rectifying device. The rectifying device exhibits an asymmetric current-voltage (I-V) response curve. Further, the system and method employ a device external to the micro object to induce the flow of charge through the rectifying device.