The present invention relates to ultrafiltration. In particular, the present invention provides nanoporous membranes having pores for generating in vitro and in vivo ultrafiltrate, devices and bioartificial organs utilizing such nanoporous membranes, and related methods (e.g., diagnostic methods, research methods, drug screening). The present invention further provides nanoporous membranes configured to avoid protein fouling with, for example, a polyethylene glycol surface coating.

A microfabricated filtration membrane including a substrate containing a plurality of micropores, an ion-selective layer, and at least two conductive layers configured to apply a voltage across the micropores. The geometry of the conductive layers matches the geometry of the micropores (or nanopores).

The present disclosure discloses a method of fabrication of free standing open pore membranes with uniform pore size and shape and ordered pore distribution, and its use for synthesis of nanoparticle patterns. The method includes applying a photoresist layer to the top surface of a substrate, heating the photoresist layer for a period of time, and exposing the photoresist layer to a dose of ultraviolet radiation through a mask having a predetermined pattern. The dose of ultraviolet radiation is controlled in intensity and time and the photoresist layer is exposed such that a top portion of the photoresist layer through which the dose of ultraviolet radiation enters the photoresist layer undergoes greater cross linking than a bottom portion of the photoresist layer immediately adjacent to the top surface of the substrate such that a cross linking gradient develops through a thickness of the photoresist layer. The mask is removed and the membrane is readily detached from the top surface of the substrate since the portion of the membrane adjacent to the top surface is less cross linked than the top surface of the membrane. The detached membrane forms a free standing patterned membrane having a preselected pattern of open pores. The method can be used with positive photoresist materials as well when deposited on a UV transparent substrate so that the photoresist can be exposed to UV from its top with photomask and UV exposure from its back of the transparent substrate without the photomask.

A nanoporous membrane fabrication method is formed using an array of sacrificial nanopillars of removable materials are printed onto a substrate. After serial deposition of overlayers of even dissimilar nature, the sacrificial nanostructures are dissolved, leaving nanoporous membrane with nanopores, channels and cavities of nanoscale dimension and geometry designed, enabling untapped and unique functions in different technological areas such as biological artificial organs, nanoelectronics, bioelectronics, molecular sensors, and biomedical applications.

A method for micro-molding a polymeric membrane and including pouring a predetermined volume of curable polymer unto a micro-fabricated mold having a post array with pillars, and overlaying the polymer with a support substrate. A spacer, such as a rubber spacer, is placed in contact with the support substrate and a force is applied to an exposed side of the spacer to compress the support substrate and the polymer together. While applying the force, the polymer is cured on the mold for a predetermined time period and at a predetermined temperature to form a polymeric membrane having a pore array with a plurality of pores corresponding to the plurality of pillars of the post array. The polymeric membrane is removed from the support substrate.

Micro- or nano-pores are produced in a membrane for various applications including filtration and sorting functions. Pores with at least one cross-sectional dimension in or near the nano-scale are provided. Device designs and processing allow for the use of thin film disposition and nano-imprinting or nano-molding to produce arrays of nano-pores in membrane materials function ing in applications such as filtration membranes, drug application/control structures, body fluid sampling structures, and sorting membranes. The nano-imprinting or nano-molding approach is utilized to create nano-elements in an organic or inorganic mold material with at least one nano-element cross-sectional dimension in or close to the nano-scale. These nano-elements can be in various shapes including slits, cones, columns, domes, and hemispheres.

Porous membranes are provided according to the invention having desirable coefficient of thermal expansion and large surface area, for example at least about 4,000 mm.sup.2. These porous membranes may be made according to an exemplary process employing lithographic patterning of a photoresist followed by development of the photoresist and etching. In one aspect, the etch barrier layer is chosen from a material that does not react with or incorporate metal or other contaminants into the membrane layer.

Porous liquid-filtering membranes having a repeatable distribution of pores of a small dimension are provided, as well as pillar templates that are used to produce such liquid filtering membranes. Also disclosed are methods of making and using the pillar templates to make porous liquid filtering membranes.

In a method for forming nanopores, two opposing surfaces of a membrane are exposed to an electrically conducting liquid environment. A nanopore nucleation voltage pulse, having a first nucleation pulse amplitude and duration, is applied between the two membrane surfaces, through the liquid environment. After applying the nanopore nucleation voltage pulse, the electrical conductance of the membrane is measured and compared to a first prespecified electrical conductance. Then at least one additional nanopore nucleation voltage pulse is applied between the two membrane surfaces, through the liquid environment, if the measured electrical conductance is no greater than the first prespecified electrical conductance.

A hole plate and a MEMS microphone arrangement are disclosed. In an embodiment a hole plate includes a substrate with a first main surface, a second main surface, and a lateral surface and a perforation structure formed within the substrate, the perforation structure having a plurality of through-holes through the substrate, wherein the through-holes and the lateral surface are a result of a simultaneous dry etching step.