Inventories (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Components of inventories
Raw materials	$ 1,627,784	$ 1,685,493
Work in process	1,778,650	2,602,990
Finished goods	1,509,606	1,745,052
Inventory gross	4,916,040	6,033,535
Less: reserve for obsolete inventory	(182,482)	(135,980)
Inventory net	$ 4,733,558	$ 5,897,555