Microactuator Using Hydrogel for Bubble Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microactuators face challenges in integrating actuator liquids into small chamber dimensions and are unsuitable for analytical applications due to the need for external liquid introduction and potential alteration of the fluid being moved.
Innovation Solution
A microactuator design utilizing a liquid-absorbing material, such as hydrogel, to store and position actuator liquid within the device, allowing for electrolysis or thermal bubble generation without external liquid introduction, enabling efficient fluid movement and control through membrane interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal bubbles are generated by local heating of the actuator liquid, then bubbles can be generated for actuator purposes, but high temperatures (>100°C) are required which are not permissible for biological applications
Solution Approach 1:
The invention changes the parameter of bubble generation from thermal (high temperature) to electrolytic (low temperature, ambient pressure). By using electrolysis instead of thermal heating, bubbles can be generated at temperatures suitable for biological applications while maintaining the actuator function.
Solution Approach 2:
The invention substitutes the thermal field (heating elements) with an electrochemical field (electrodes performing electrolysis). This replacement allows bubble generation through electrochemical reactions rather than thermal heating, eliminating the need for high temperatures in biological applications.
2Temperature
If electrodes are introduced into the actuator liquid for electrolysis, then bubbles can be generated without high temperature, but the actuator liquid must be introduced into chambers via channels after microactuator completion which is difficult in small dimensions
Solution Approach 1:
The invention applies preliminary action by pre-loading the actuator liquid into the liquid-absorbing material during the manufacturing process, before the microactuator is completed and sealed. This eliminates the need for post-manufacturing liquid introduction through channels, solving the integration difficulty in small dimensions.
Solution Approach 2:
The invention introduces a liquid-absorbing material as an intermediary component between the electrodes and the actuator liquid. This material absorbs and stores the liquid in advance, serving as a reservoir that releases liquid to the electrodes during operation, thereby eliminating the need for external liquid introduction channels.
3Device complexity
If the fluid to be moved itself serves as actuator fluid for bubble generation, then no external liquid is needed, but the fluid being moved is altered which is unsuitable for analytical applications
Solution Approach 1:
The invention segments the liquid system into two separate functions: the actuator liquid (stored in liquid-absorbing material) serves for bubble generation, while the fluid to be moved flows through separate channels. This segmentation prevents the actuator liquid from mixing with or altering the sample fluid, maintaining sample integrity for analytical applications.
Solution Approach 2:
The liquid-absorbing material acts as an intermediary reservoir that separates the actuator liquid from the fluid to be moved. By storing and supplying actuator liquid independently, it prevents direct contact between the actuator liquid and the sample fluid, thereby preserving the integrity of the fluid being analyzed.
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 microactuator can efficiently move and control fluids by generating bubbles within the actuator liquid, eliminating the need for external liquid introduction and maintaining the integrity of the fluid being moved, making it suitable for analytical applications.
Implementation Method 1
a liquid-absorbing material, such as hydrogel, to store and position actuator liquid within the device
Implementation Method 2
bubbles can be generated in a liquid containing water by means of electrolysis. If electrodes are introduced into the actuator liquid in this variant and these are electrically connected, the following reactions take place at the electrodes: Anode (+): 2H2O → O2 + 4H+
Implementation Method 3
micro-bubbles generated in the actuator liquid can be used to generate an actuator effect. Such microbubbles can be generated, for example, by local heating of the actuator liquid in the form of thermal microbubbles
Implementation Method 4
the chambers are covered with a membrane. Liquid with a low boiling point can be fed into the chambers through an inlet. If the liquid is heated with the heating elements, thermal bubbles form, which move the membrane upwards and increase the volume of the chambers. The upwardly pressed membrane in turn acts on a fluid to be moved that is directly or indirectly connected to the microfluidic actuator, the fluid being pressed in the direction of a fluid outlet.
Data Source
Figure 1~2
Figure 3~4
Figure 5~8
AI summary
The micro actors (1) has a partly water containing actor fluid (3). The actor fluid is introduced in the fluid absorbing material. The fluid absorbing material consists of a hydro gel (6) which is a super absorbent polymer contains polyacrylic acid. The hydro gel consists of a thermally stimulated hydro gel. The micro actuator has a flexible diaphragm brought in contact with the fluid (2). An independent claim is included method for moving and controlling the movements of fluids, has a microactor.