TECHNOLOGY FOCUS - BIOLOGY - Preferred Material: The fluid is a biological fluid from saliva, blood, serum, cerebral spinal fluid, mucosal secretions, urine, or seminal fluids. It is an aqueous solution. The organism is a cell line, an isolated cell, a bacterium, a virus, a protoplast, fungus, and/or a parasite. Preferred Component: The nanoscale membrane comprises a cell surface receptor, an antibody, a ligand, and/or a biological reagent, on the surface of one or both sides of the membrane or within the pores of membrane.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: Simultaneously forming spaced pores in the membrane is carried out by converting the amorphous semiconductor material, before or after etching, to form a crystalline semiconductor material. Converting is carried out by annealing the amorphous semiconductor material at a temperature and duration to induce crystallization. Masking comprises forming an incomplete silicon dioxide film on the opposite side of the silicon substrate. Etching is carried out using an etchant that has a silicon/silicon dioxide selectivity that is greater than 10000. It is carried out using an etchant comprising ethylenediamine, pyrocatechol, pyrazine, and water. The method comprises removing the sacrificial films after etching and after the step of simultaneously forming spaced pores. Removing comprises exposing the sacrificial silicon dioxide films to a buffered oxide etchant solution, or a hydrofluoric acid etchant solution. Preferred Component: The nanoscale film comprises an amorphous semiconductor material, and each sacrificial film is an oxide film. The crystalline semiconductor material is in the form of a polycrystalline or a nanocrystalline material. Preferred Material: Each oxide film is silicon dioxide; and the substrate is silicon.    TECHNOLOGY FOCUS - METALLURGY - Preferred Material: The semiconductor material is undoped silicon or germanium, p-doped silicon or germanium, n-doped silicon or germanium, or a silicon-germanium alloy. It is silicon or germanium doped with boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, and/or germanium. It is in a crystalline form. Preferred Component: The nanoscale membrane comprises a coating of a metal at least partially covering its one side, where metal is from gold, silver, copper, platinum, aluminum, chromium, titanium, tungsten, lead, tin, palladium, or their alloys.    TECHNOLOGY FOCUS - POLYMERS - Preferred Material: The compound is protein, colloidal nanoparticle, organic molecular system, inorganic nanoparticle, dissolved ions, drugs, sugars, aqueous salts, metals, semiconductors, pharmaceutical compound, nucleic acid, enzyme, lipid, carbohydrate, and/or polypeptides.