Porous Biodegradable Microneedles for Strong, Rapid ISF Sampling
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Solution Overview
Problem
Existing microneedles for interstitial fluid sampling lack sufficient mechanical strength and are difficult to manufacture efficiently, and current devices for blood glucose monitoring are invasive and inaccurate.
Innovation Solution
A porous microneedle manufactured using biodegradable microspheres bonded through heat treatment, integrated with a paper substrate sensor, allowing for rapid and minimally invasive glucose level measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a hollow microneedle structure is used for ISF sampling, then sampling capability is improved, but mechanical strength deteriorates and fragments remain in skin
Solution Approach 1:
The patent employs a porous microneedle structure where interconnected pores replace the hollow cavity. This porous configuration allows ISF to enter through multiple pathways while the solid continuous matrix maintains mechanical strength. The pores are formed by removing sacrificial particles (salt, sugar, or starch) from a composite precursor, creating a robust yet permeable structure that prevents fragmentation.
2Reliability
If a biodegradable polymer microneedle with porous structure is used, then biocompatibility is improved, but manufacturing complexity increases and mechanical strength deteriorates
Solution Approach 1:
The patent uses a composite precursor material consisting of biodegradable polymer (PLA or PLGA) combined with sacrificial particles (salt, sugar, or starch). This composite approach allows simple processing through conventional techniques like extrusion or molding, followed by easy removal of the sacrificial component. The resulting porous structure maintains biocompatibility while avoiding manufacturing complexity and strength loss.
3Manufacturing precision
If salt-leaching method is used to create porous microneedle, then pore structure control is improved, but processing complexity increases and mechanical strength deteriorates
Solution Approach 1:
The patent controls pore structure by adjusting parameters of the sacrificial particles (size, shape, concentration) and processing conditions (removal method, temperature). By changing these parameters, the pore diameter, porosity, and interconnectivity can be precisely controlled. This approach maintains processing simplicity compared to traditional salt-leaching while achieving superior mechanical strength through the composite precursor structure.
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 microneedle provides high mechanical strength for pain-free sampling and accurate measurement of interstitial fluid components, such as glucose and cholesterol, with a simple manufacturing process.
Implementation Method 1
can allow rapid sampling of an interstitial fluid or the like by capillary force
Implementation Method 2
a porous microneedle can be manufactured using microspheres of a biodegradable polymer such as polylactic acid by a heat treatment
Data Source
AI summary
Provided are an inspection device including a porous microneedle that has high mechanical strength and can allow rapid sampling of an interstitial fluid or the like by capillary force, and a process for manufacturing the microneedle.An inspection device comprises: a porous microneedle; and a paper substrate sensor having at least one measurement region, in which the microneedle is formed of microspheres of a biodegradable material.