Abstract: Disclosed herein are a solder alloy composition comprising Sn—Bi—In base solder particles. The Sn—Bi—In base solder particles is characterized by having an average diameter less than 10 ?m, and the Sn—Bi—In base alloy comprises 12-22% of Sn, 33-43% of Bi and 45-55% by weight. Also disclosed herein is a method for producing the Sn—Bi—In base solder particles. The method mainly includes the steps of, sintering a mixture comprising tin (Sn), bismuth (Bi) and indium (In) at a designated weight ratio to produce a bulk alloy; dissolving the bulk alloy to produce an alloy solution; and subjected the alloy solution to ultrasonication at a first temperature of about 65-85° C. and then cooling at a second temperature of about 0-25° C., thereby produces the present Sn—Bi—In base solder particles.

Abstract: A porous copper-based filter material that is electrodeposited with nanotwin copper to provide anti-pathogenic properties, particularly against Covid-19 or the SARS virus. The nanotwin copper is a thin layer of (111) oriented nanotwin copper microstructure.