An amorphous thermoset thiourethane polymer, comprising a sequential chain of a first type of monomer covalently bonded to a second type of monomer via thiourethane linkages, wherein the first type of monomer includes two or more thiol functional groups and the second type of monomer includes two or more isocyanate functional groups. Methods of synthesizing the polymer, bio-electronic devices comprising the polymer and methods of manufacturing such devices are disclosed.