Microneedle Sensor Air Venting for Skin Irritation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing body monitoring devices using microneedle sensors for transcutaneous glucose monitoring face issues with skin irritation and bacterial development due to prolonged contact and immobility, as well as unreliable measurement results and patient discomfort from iontophoresis-based systems.
Innovation Solution
A body monitoring system featuring a sensor with a network of microneedles housed in channels with open passages for air renewal, a semi-permeable barrier to prevent water entry, and a substrate design that minimizes skin deformation and irritation, allowing for reduced microneedle density and independent electrode operation for precise analyte measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If microneedle sensors are used for transcutaneous monitoring, then continuous measurement is enabled, but skin irritation and bacterial development occur due to prolonged contact and immobility
Solution Approach 1:
The microneedle array is segmented into multiple independent microneedles (at least three) that can be spatially distributed on the skin. This segmentation allows different regions of skin to be monitored over time, reducing localized irritation and bacterial buildup at any single site while maintaining continuous monitoring capability.
Solution Approach 2:
The system enables dynamic repositioning or rotation of microneedle engagement points on the skin. By dynamically changing which microneedles are in contact with the skin at any given time, the system maintains continuous monitoring while preventing prolonged stationary contact that causes irritation and bacterial development.
2Ease of operation
If iontophoresis is used to extract interstitial fluid, then transcutaneous measurement is achieved, but patient discomfort and unreliable results occur
Solution Approach 1:
The system extracts only the necessary interstitial fluid samples through passive capillary action or minimal pressure, rather than using aggressive iontophoresis. This selective extraction of fluid without strong electrical fields reduces patient discomfort while maintaining measurement capability.
Solution Approach 2:
The microneedles serve as intermediaries that passively access interstitial fluid through their porous structure or capillary channels, eliminating the need for iontophoresis electrical fields. This intermediary approach provides reliable fluid access without the harmful effects of electrical extraction.
3Measurement precision
If microneedle density is increased for better monitoring coverage, then measurement precision improves, but skin irritation and bacterial growth are exacerbated
Solution Approach 1:
The monitoring function is segmented across multiple microneedles spaced at optimized distances from each other. This segmentation provides sufficient measurement precision through spatial distribution while maintaining skin-friendly density that prevents excessive irritation and bacterial growth.
Solution Approach 2:
Different regions of the microneedle array have optimized local densities based on their specific monitoring functions. Critical measurement zones have higher precision microneedle density, while peripheral zones have lower density to minimize skin irritation and bacterial development in those areas.
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 solution significantly reduces skin irritation, bacterial development, and discomfort while enhancing measurement precision and reliability by maintaining an air environment around microneedles and using fewer microneedles for effective analyte monitoring.
Implementation Method 1
the substrate comprises at least one open passage, and preferably at least two open passages, ensuring a connection between the channel and the exterior so as to renew the air surrounding the base of one or more microneedles
Implementation Method 2
the sensor comprises a passage connecting the channel to the outside and comprises a barrier made of semi-permeable material, either impermeable to water and permeable to air, the sensor comprises a passage connecting the channel to the outside, said passage having a section adapted to prevent the entry of water by capillary repulsion
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a sensor for a body monitoring system comprising at least one substrate intended to come into contact with the skin and at least one microneedle, the microneedle being fixedly mounted on the substrate, the substrate comprising an open channel that surrounds the base of the microneedle, the microneedle having a central axis of symmetry, and the channel having a minimum height in the direction of the central axis that is greater than 20 µm and having a minimum width that is greater than 200 µm in a radial direction to the central axis, the channel forming a cavity in which the microneedle is housed.