Note 11 - Segment Reporting - Segment Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022		Mar. 31, 2021	Dec. 31, 2021
Assets	$ 32,006,677	[1]	$ 39,206,000	$ 35,524,229
Revenue	4,655,727	[1]	3,365,860
Operating (loss) income	(1,005,988)	[1]	(1,618,787)
Pretax (loss) income	(997,340)	[1]	(1,505,550)
Segment Reconciling Items [Member]
Assets	15,000		24,000
Intersegment Eliminations [Member]
Revenue	(44,000)		(96,000)
Operating (loss) income	(706,000)		(929,000)
Pretax (loss) income	(706,000)		(929,000)
CVD [Member] | Operating Segments [Member]
Assets	22,575,000		29,659,000
Revenue	2,827,000		2,006,000
Operating (loss) income	(736,000)		(575,000)
Pretax (loss) income	(726,000)		(590,000)
SDC [Member] | Operating Segments [Member]
Assets	7,756,000		6,116,000
Revenue	1,415,000		827,000
Operating (loss) income	442,000		(5,000)
Pretax (loss) income	442,000		(5,000)
Materials [Member] | Operating Segments [Member]
Assets	1,661,000		3,407,000
Revenue	458,000		629,000
Operating (loss) income	(6,000)		(110,000)
Pretax (loss) income	$ (7,000)		$ 18,000

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