Microneedle for biosensing and method of fabrication

Abstract

A microneedle for biosensing and a method of fabrication are disclosed. The method includes depositing at least one layer of photoresist on a broad surface of a substrate, and the photoresist is subsequently patterned to define features of the microneedle. A first etching treatment in the form of deep reactive ion etching (DRIE) is applied to etch the substrate into first structure where the etching depth is less than the substrate total depth so as to create at least one sacrificial feature adjacent to the portions of the substrate under the photoresist. A second etching treatment in the formof isotropic wet etching is subsequent applied where the etching of the at least one sacrificial feature causes a gradual variation in etching rate along the length of the microneedle such that the tip of the microneedle is sharpened.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 677,521, filed May 29, 2018, entitled "MICRONEEDLE FORBIOSENSING AND METHOD OF FABRICATION," which is hereby incorporated by reference in its entirety. technical field [0003] The present invention generally relates to the field of medical equipment, and more specifically relates to a novel and practical microneedle device for biosensing in the field of medical equipment. Background technique [0004] Biosensing devices are widely used in the field of medical devices to sample one or more fluids from the user for detection and to monitor the body's chemical reactions. However, microneedles and microneedle arrays can penetrate the user's skin in a simple and painless manner, and can be operated by the user at home, so they have shown broad prospects in the above-mentioned fields. [0005] However, current fabrication methods and materials h...

AI Technical Summary

Problems solved by technology

[0005] However, current fabrication methods and materials have limitations in fabricating effective microneedles and microneedle arrays

For example, in out-of-plane fabrication methods using semiconductor materials such as silicon, the microneedle length is limited by the anisotropic Bosch etching process and the thickness of the substrate wafer used to fabricate the microneedles, and / or the structural integrity of the out-of-plane structure. limitations, this structural integrity can limit the type and amount of fluid that the microneedles can remove from the user

Although planar fabrication techniques can produce relatively long microneedles, the microneedles produced by this technology are often not sharp enough to overcome skin elasticity during device insertion, or, even if the microneedles can overcome skin elasticity, the needle tip (such as wedge-shaped needle tip ) also often cut through the skin like a scalpel, causing bleeding and preventing the collection of interstitial fluid

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