Microfluidic Device with Punch-Actuated Diaphragm for Reagent Release

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Solution Overview

Problem

Microfluidic devices face challenges in storing and releasing liquids, particularly moisture-sensitive reagents, in a long-term stable and hygienic manner, with existing solutions often involving manual pipetting or contamination risks.

Innovation Solution

A microfluidic device with a chamber substrate, a cover substrate, a flexible diaphragm, and a punch unit that deflects the diaphragm to release fluids from a fluid chamber, allowing for long-term storage and controlled release without direct contact with the punch unit, using a polymer substrate with good barrier properties and a barrier film for containment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical punch unit is used to release reagents, then the release reliability is improved, but the risk of contamination increases

Engineering Contradiction:

Improverelease reliabilityVSAvoidcontamination risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The device is divided into separate functional components: a reusable punch unit for mechanical actuation and a disposable fluid chamber assembly containing the reagent. This segmentation allows the punch unit to be sterilized and reused while the fluid chamber is discarded after single use, eliminating cross-contamination risks while maintaining reliable mechanical release functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fluid chamber assembly is designed as a disposable component that is discarded after single use. This eliminates the need to sterilize the chamber between uses and prevents contamination from residual fluids, while the more expensive punch unit can be reused. The disposable nature ensures long-term stability during storage and hygienic conditions during use.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Extent of automation

If reagents are pre-stored on the cartridge, then automation is improved, but contamination risks increase

Engineering Contradiction:

ImproveautomationVSAvoidcontamination risk

Core Design Contradiction:

Extent of automationVSObject-affected harmful factors

Solution Approach 1:

Reagents are pre-loaded into sealed fluid chambers during manufacturing before the device reaches the user. This preliminary action allows for controlled filling in a sterile environment during production, eliminating the need for manual pipetting by the end user. The chambers remain hermetically sealed until activation, preventing contamination during storage and transport while enabling automated operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The reagent storage function is extracted into separate hermetically sealed fluid chambers that are integrated into the cartridge but remain isolated from the external environment until needed. This extraction allows automated handling while maintaining sterile barriers, as the reagents are contained in discrete units that are only opened at the point of use through the punch mechanism.

Inventive Principle:

Principle #2Taking out (Extraction)

3Stability of the object's composition

If a flexible diaphragm is used to contain fluid, then the storage stability is improved, but the device complexity increases

Engineering Contradiction:

Improvestorage stabilityVSAvoiddevice complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

A flexible diaphragm made of elastomeric material is used to seal the fluid chamber opening. This thin flexible film provides hermetic sealing to maintain long-term storage stability of the reagent while allowing simple integration into the chamber structure. The diaphragm's flexibility enables it to conform to the chamber geometry and provides reliable sealing without requiring complex mechanical assemblies.

Inventive Principle:

Principle #30Flexible shells and thin films

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 reliable, long-term storage and controlled release of reagents, reducing contamination risks and allowing for reusability of the punch unit, while maintaining hygiene and simplifying handling and production processes.

Implementation Method 1

a pressure-driven manner, be opened via deflection of a flexible diaphragm

Methodology Applied

Scientific EffectPressure-driven deflection: Pressure Increase

Implementation Method 2

The diaphragm is designed to be deflected when a pressure is applied to the diaphragm

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS11065621B2Microfluidic device, production method, and method for operating a microfluidic device

Publication Date: 2021.07.20 ROBERT BOSCH GMBH

AI summary

A microfluidic device includes a chamber substrate, a cover substrate, a flexible membrane, and a punch unit. The chamber substrate includes a fluid chamber configured to receive a fluid and having a fluid chamber opening. The cover substrate includes a punch opening lying opposite the fluid chamber opening. The flexible membrane is positioned between the chamber substrate and the cover substrate, and spans the punch opening and the fluid chamber opening. The punch unit is configured to move into the fluid chamber through the punch opening in order to deflect the flexible membrane into the fluid chamber so as to enable the fluid to flow out of the fluid chamber when fluid is received in the fluid chamber.