Abstract: Microfabricated, asymmetrical, reservoir-containing particles for use in the oral delivery of biopolymer therapeutic agents such as peptides, proteins and oligonucleotides are disclosed. The particles are encapsulated in enteric-coated capsules or tablets to provide passage through the stomach and release of a suspension of the particles in the intestinal lumen. The particles have a selected shape, and uniform dimensions preferably in the 100 &mgr;m to 1 mm range. The reservoirs open to the face of the particle and are filled with a therapeutic agent and selected excipients. The excipients are selected to delay the dissolution/release of the agent from the particle reservoirs for 5-60 minutes after the particle is released in the intestinal lumen. Alternatively, the pore is plugged with an erodable material.

Abstract: A suspension of microfabricated microdevices for use in therapeutic applications is disclosed. The microdevices have a selected shape, and uniform dimensions preferably in the 100 nm to 10 Am range. Also disclosed are microfabrication methods for making such microdevices.

Abstract: Microfabricated filters utilizing a bulk substrate structure and a thin film structure and a method for constructing such filters. The pores of the filters are defined by spaces between the bulk substrate structure and the thin film structure and are of substantially uniform width, length and distribution. The width of the pores is defined by the thickness of a sacrificial layer and therefore may be smaller than the limit of resolution obtainable with photolithography. The filters provide enhanced mechanical strength, chemical inertness, biological compatibility, and throughput. The filters are constructed using relatively simple fabrication techniques. Also, microfabricated containment wells and capsules constructed with such filters for the immunological isolation of cell transplants and a method for constructing such containment wells and capsules.

Abstract: This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures.

Abstract: A microfabricated containment capsule has a bulk substrate delimiting a cavity with a boundary, a first portion of which constitutes an inner wall of a solid portion of the bulk substrate. The bulk substrate also provides at a second portion of the boundary a membrane joined to one side of the bulk substrate, the membrane having at least one porous area with controlled pores.

Abstract: Surface micromachining and bulk micromachining are employed for realizing a porous membrane with bulk support for a microparticle filter. The filter is manufactured by a process employing a thin film etch-stop, in which the bulk substrate is etched using a first etching process followed by etching of the etch stop and of material within pores of a filter layer using a second etching process. The filter is sufficiently sturdy to allow for easy handling. It may be used as a diffusion barrier and under high pressures. The disclosed fabrication method is simple, reliable, and integrated-circuit compatible, and thus amenable to mass production. Electronic circuitry may be integrated on the filter surface, as may be desired for several purposes, such as fluid characterization, filter self-cleaning, or charging of the filter surfaces. Methods are shown for the realization of biological containment capsules based on this microfilter.

Abstract: A thin film filter fabricated using surface micromachining. The width of the filter pores is determined by the thickness of a sacrificial thin-film layer. This dimension can be precisely controlled, and may be as small as about 50 angstroms. The pore length may also be determined by the thickness of thin film layers and can therefore be smaller than the limit of resolution obtainable with photolithography. The filters are suitable for use at high temperatures and with many harsh solvents.

Abstract: A microfabricated filter made up of two bonded substrate structures, each consisting of single crystalline silicon can optionally be formed into a capsule. The pores of the filter consist of one or more channels disposed between the two substrate structures. The width of the channels are defined by a thickness of a sacrificial layer formed on one of the substrate structures. The filter includes pores having a precisely controlled pore width which may be as small as 5 nanometers. The filter provides a relatively high mechanical strength relative to filters having polycrystalline silicon structures and also has a high throughput and can be modified to have high resistance to adsorption of particles.

Abstract: The present invention provides a capsule made of a biologically compatible material with sufficient mechanical strength to form a very thin membrane shell having at least a region with approximately uniformly sized and spaced holes or pores that are large enough to let a desired biologically active molecular product through, while blocking the passage of all larger immunological molecules. The present invention thus provides an immunological isolation of cell transplants contained therein. The present invention also provides a free standing thin film structure that may be used as a component of such a capsule and method for the fabrication of such component and capsules.

Abstract: Microfabricated filters utilizing a bulk substrate structure and a thin film structure and a method for constructing such filters. The pores of the filters are defined by spaces between the bulk substrate structure and the thin film structure and are of substantially uniform width, length and distribution. The width of the pores is defined by the thickness of a sacrificial layer and therefore may be smaller than the limit of resolution obtainable with photolithography. The filters provide enhanced mechanical strength, chemical inertness, biological compatibility, and throughput. The filters are constructed using relatively simple fabrication techniques. Also, microfabricated containment wells and capsules constructed with such filters for the immunological isolation of cell transplants and a method for constructing such containment wells and capsules.

Abstract: Surface micromachining and bulk micromachining are employed for realizing a porous membrane with bulk support for a microparticle fiter. The filter is sufficiently sturdy to allow for easy handling. It may be used as a diffusion barrier and under high pressures. The disclosed fabrication method is simple, reliable, and integrated-circuit compatible, and thus amenable to mass production. Electronic circuitry may be integrated on the filter surface, as may be desired for several purposes, such as fluid characterization, filter self-cleaning, or charging of the filter surfaces. Methods are shown for the realization of biological containment capsules based on this microfilter.

Abstract: A thin film filter fabricated using surface micromachining. The width of the filter pores is determined by the thickness of a sacrificial thin-film layer. This dimension can be precisely controlled, and may be as small as about 50 angstroms. The pore length may also be determined by the thickness of thin film layers and can therefore be smaller than the limit of resolution obtainable with photolithography. The filters are suitable for use at high temperatures and with many harsh solvents.