Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Significant Accounting Policies

Schedule of vendors which accounted for 10% or more of the Company's raw material purchases

		Years Ended December 31,
Vendor	Supplies	2015			2014
A	Substrates		38	%		27	%
B	Substrates		20	%		*
C	Substrates		*			14	%
D	Catalysts		*			10	%

*           less than 10%

Schedule of warrant liability measured at fair value on a recurring basis

The valuation inputs hierarchy classification for the warrant liability measured at fair value on a recurring basis is summarized as follows (in thousands):

Warrant Liability	Level 1		Level 2		Level 3
December 31, 2015		—		—	$	3,072
December 31, 2014		—		—	$	1,474

Schedule of reconciliation of warrant liability

        The following is a reconciliation of the warrant liability measured at fair value using Level 3 inputs (in thousands):

	Years Ended December 31,
	2015			2014
Balance at beginning of period	$	1,474		$	939
Issuance of common stock warrants		4,215			2,978
Exercise of common stock warrants		—			(2,949	)
Remeasurement of common stock warrants		(2,617	)		506
Balance at end of period	$	3,072		$	1,474