Nano-silver footwear orthotic with insert and method of manufacture

Abstract

A nano-silver footwear orthotic includes at least two removable inserts. The footwear orthotic and/or the at least two removable inserts are composed of a nano-silver copolymer being copolymer with silver nano-particles therein. In one aspect, the copolymer is a thermoplastic elastomer. The nano-silver copolymer has anti-microbial effects and ensures biocompatibility with known undesirable microorganisms. Corresponding manufacturing processes prepare the silver nano-particles with a silver nitrate solution and a sodium borohydride solution and add the silver nano-particles to a master batch and a base material to form the nano-silver copolymer in a mold cavity. The mold cavity may be constructed to form the nano-silver footwear orthotic and/or a removable insert therein. Alternatively, the nano-silver copolymer may be formed within the nano-silver footwear orthotic itself to form a removable insert. Tests showing the content of silver nano-particles in a silver—copolymer mixture and corresponding antimicrobial effect tests show antimicrobial effects against bacteria known to cause foot odor and itchiness.

1 . An anti-microbial footwear orthotic comprising
 an orthotic including a customizable support section defining at least one opening therein;   multiple inserts of varying profile for insertion into the at least one opening one at a time;   at least one of the orthotic and the multiple inserts being copolymer with silver nano-particles therein at a therapeutic ratio to be an effective antibacterial agent.   
     
     
         2 . The anti-microbial footwear orthotic of  claim 1 , the therapeutic ratio being about 0.036 to 0.36 percent of the silver nano-particles to the copolymer by weight. 
     
     
         3 . The anti-microbial footwear orthotic of  claim 1 , the copolymer being a thermoplastic elastomer. 
     
     
         4 . A method of manufacturing an anti-microbial footwear orthotic comprising
 preparing silver nano-particles by reducing the silver from a silver nitrate and sodium borohydride solution;   preparing a master batch of the prepared silver nano-particles with a copolymer;   molding a footwear orthotic from the master batch, the molded footwear orthotic including copolymer with the prepared silver nano-particles therein at a therapeutic ratio to be an effective antibacterial agent.   
     
     
         5 . The method of  claim 4 , the therapeutic ratio to be an effective antibacterial agent being about 0.036 to 0.36 percent of the silver nano-particles to the thermoplastic elastomer by weight.