Note 12 - Segment Reporting - Segment Information (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Assets		$ 40,935,925	$ 46,723,052
Revenue		16,920,219	19,646,652
Operating (loss)/income		(7,823,957)	(4,984,715)
Pretax (loss)/income		(7,602,307)	(4,913,750)
Corporate, Non-Segment [Member]
Assets
Revenue
Operating (loss)/income		(3,151,000)	(3,333,000)
Pretax (loss)/income		(3,151,000)	(3,333,000)
Intersegment Eliminations [Member]
Assets	[1]	(9,000)	(9,000)
Revenue	[1]	(450,000)	(702,000)
Operating (loss)/income	[1]
Pretax (loss)/income	[1]
CVD [Member] | Operating Segments [Member]
Assets		31,284,000	34,374,000
Revenue		10,385,000	14,065,000
Operating (loss)/income		(863,000)	(1,811,000)
Pretax (loss)/income		(878,000)	(1,782,000)
SDC [Member] | Operating Segments [Member]
Assets		6,068,000	6,003,000
Revenue		4,429,000	4,498,000
Operating (loss)/income		473,000	696,000
Pretax (loss)/income		481,000	719,000
Materials [Member] | Operating Segments [Member]
Assets		3,593,000	6,355,000
Revenue		2,556,000	1,786,000
Operating (loss)/income		(4,283,000)	(537,000)
Pretax (loss)/income		$ (4,054,000)	$ (518,000)

[1] All elimination entries represent intersegment transactions eliminated in consolidation for external reporting. 2020 Materials segment includes an impairment charge of $3.6 million related to the Tantaline product line