A method of making a semi-conducting microfiber. The method includes melting a semi-conducting solid polymer material to form a polymer melt, dipping a tip of a tool into the polymer melt, and lifting the tip of the tool away from the polymer melt, forming a microfiber. A semiconducting microfiber. The semiconducting microfiber contains a non-conjugated semiconducting polymer matrix containing crystalline aggregates with intentionally placed conjugation-break spacers along the polymer backbone. A device containing a plurality of semiconducting microfibers. Each of the semiconducting fibers contains a non-conjugated semiconducting polymer matrix containing crystalline aggregates with intentionally placed conjugation-break spacers along the polymer backbone. An apparatus to make a semiconducting microfiber. The apparatus contains a container to melt and hold the molten polymer, a tool dipped into the polymer melt, and a means of lifting tip of the tool away from a surface of the polymer melt forming a microfiber.