Abstract:
A method for manufacturing porous microstructures in a silicon semiconductor substrate, porous microstructures manufactured according to this method, and the use thereof.
Abstract:
A method for manufacturing porous microstructures in a silicon semiconductor substrate, porous microstructures manufactured according to this method, and the use thereof.
Abstract:
Out-of-plane microneedle manufacturing process comprising the simultaneous creation of a network of microneedles and the creation of a polygonal shaped hat (2) above each microneedle (1) under formation, said process comprising the following steps: providing bridges (3) between the hats (3), maintaining the bridges (3) during the remaining microneedle manufacturing steps, removing the bridges (3), together with the hats (2), when the microneedles (1) are formed.
Abstract:
A method for forming a hollow microneedle structure includes processing the front side of a wafer to form at least one microneedle projecting from a substrate and a through-bore passing through the microneedle and through a thickness of the substrate. An entire length of the through-bore is formed by a dry etching process performed from the front side of the wafer. Most preferably, upright surfaces of the microneedle structure and the through bore of the structure are formed by dry etching performed via a single mask with differing depths obtained by harnessing aspect ratio limitations of the dry etching process.
Abstract:
A method of wet etching produces high-precision microneedle arrays for use in medical applications. The method achieves precise process control over microneedle fabrication, at single wafer or batch-level, using wet etching of silicon with potassium hydroxide (KOH) solution by accurately identifying the etch time endpoint. Hence, microneedles of an exactly required height, shape, sharpness and surface quality are achieved. The outcome is a reliable, reproducible, robust and relatively inexpensive microneedle fabrication process. Microneedles formed by KOH wet etching have extremely smooth surfaces and exhibit superior mechanical and structural robustness to their dry etched counterparts. These properties afford extra reliability to such silicon microneedles, making them ideal for medical applications. The needles can also be hollowed. Wet etched silicon microneedles can then be employed as masters to replicate the improved surface and structural properties in other materials (such as polymers) by moulding.
Abstract:
A method of manufacturing a hollow micro-needle structure includes the steps of: disposing a first mask layer and a second mask layer respectively aside a first substrate and aside a rear surface of the first substrate, wherein the first substrate is transparent to predetermined light; forming a photoresist layer on the front surface of the first substrate and the first mask layer; providing the predetermined light to illuminate the first substrate in a direction from the rear surface to the front surface so as to expose the photoresist layer to form an exposed portion and an unexposed portion; and removing the unexposed portion to form the micro-needle structure, which is formed by the exposed portion. The micro-needle structure has an inclined sidewall and a through hole surrounded by the inclined sidewall.
Abstract:
The present invention is related to a flexible substrate structure for microneedle arrays and its manufacturing method, whose structure mainly comprising: tapered shape objects and flexible substrate. Wherein, structure of the tapered shape object is composed of a tip, sidewalls, and a base. Meanwhile, the flexible substrate winds tightly around sidewalls of tapered shape objects and is set up on, yet covers the base surface of tapered shape object which faces the tip of tapered shape object. Because the structure applies a flexible substrate along with tapered shape objects, hence, the fit-to-body capability is increased and allows thereof more appropriate for backside drug delivery, as well as sufficiently bring the characteristic of large-area manufacturing into full play.
Abstract:
A method of manufacturing a moldable microneedle array (54) is described comprising providing a negative mold insert (44) characterized by a negative image of microneedle topography wherein at least one negative image of a microneedle is characterized by an aspect ratio of between about 2 to 1 and about 5 to 1. The negative mold insert (44) is used to define a structured surface of a negative mold cavity (42). Molten plastic material is injected into the heated negative mold cavity. The molten plastic material is subsequently cooled and detached from the mold insert to provide a molded microneedle array (54). One manner of using microneedle arrays of the present invention is in methods involving the penetration of skin to deliver medicaments or other substances and/or extract blood or tissue through the skin.
Abstract:
Improved microneedle arrays are provided having a sufficiently large separation distance between each of the individual microneedles to ensure penetration of the skin while having a sufficiently small separation distance to provide high transdermal transport rates. A very useful range of separation distances between microneedles is in the range of 100–300 microns, and more preferably in the range of 100–200 microns. The outer diameter and microneedle length is also very important, and in combination with the separation distance will be crucial as to whether or not the microneedles will actually penetrate the stratum corneum of skin. For circular microneedles, a useful outer diameter range is from 20–100 microns, and more preferably in the range of 20–50 microns. For circular microneedles that do not have sharp edges, a useful length for use with interstitial fluids is in the range of 50–200 microns, and more preferably in the range of 100–150 microns; for use with other biological fluids, a useful length is in the range of 200 microns–3 mm, and more preferably in the range of 200–400 microns. For circular microneedles having sharp side edges, a useful length for use with interstitial fluids is in the range of 50–200 microns, and more preferably in the range of 80–150 microns; for use with other biological fluids, a useful length is again in the range of 200 microns–3 mm, and more preferably in the range of 200–400 microns. For solid microneedles having a star-shaped profile with sharp edges for its star-shaped blades, a useful length for use with interstitial fluids is in the range of 50–200 microns, and more preferably in the range of 80–150 microns; for use with other biological fluids, a useful length is again in the range of 200 microns–3 mm, and more preferably in the range of 200–400 microns, while the radius of each of its blades is in the range of 10–50 microns, and more preferably in the range of 10–15 microns.
Abstract:
A method and apparatus for puncturing a surface for extraction, in situ monitoring, and/or substance delivery uses microneedles with improved properties. Applications include easy to handle glucose monitoring using a group of hollow out-of-plane silicon microneedles to sample substances in interstitial fluid from the epidermal skin layer.