Intangible assets - Schedule of Finite-Lived Intangible Assets (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Schedule of Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 450,365	$ 286,070
Finite-Lived Intangible Assets, Accumulated Amortization	(78,345)	(44,449)
Intangible assets, net	372,020	241,621
Product Certifications
Schedule of Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	235,482	218,168
Finite-Lived Intangible Assets, Accumulated Amortization	(57,798)	(38,254)
Intangible assets, net	177,684	179,914
Patents
Schedule of Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	214,883	67,902
Finite-Lived Intangible Assets, Accumulated Amortization	(20,547)	(6,195)
Intangible assets, net	$ 194,336	$ 61,707