Note 12 - Segment Reporting - Segment Information (Details) - USD ($)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Assets		$ 46,723,052	$ 51,835,562
Revenue		19,646,652	24,334,331
Operating (loss)/income		(4,984,715)	(5,254,519)
Pretax (loss)/income		(4,913,750)	(5,557,583)
Corporate, Non-Segment [Member]
Assets
Revenue
Operating (loss)/income		(3,333,000)	(3,164,000)
Pretax (loss)/income		(3,333,000)	(3,164,000)
Intersegment Eliminations [Member]
Assets	[1]	(9,000)	(9,000)
Revenue	[1]	(702,000)	(1,022,000)
Operating (loss)/income	[1]
Pretax (loss)/income	[1]
CVD [Member] | Operating Segments [Member]
Assets		34,374,000	39,788,000
Revenue		14,065,000	17,860,000
Operating (loss)/income		(1,811,000)	(1,754,000)
Pretax (loss)/income		(1,782,000)	(1,691,000)
SDC [Member] | Operating Segments [Member]
Assets		6,003,000	4,870,000
Revenue		4,498,000	5,503,000
Operating (loss)/income		696,000	958,000
Pretax (loss)/income		719,000	987,000
Materials [Member] | Operating Segments [Member]
Assets		6,355,000	7,187,000
Revenue		1,786,000	1,993,000
Operating (loss)/income		(537,000)	(1,295,000)
Pretax (loss)/income		$ (518,000)	$ (1,690,000)

[1] All elimination entries represent intersegment transactions eliminated in consolidation for external financial reporting.