Note 9 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Mar. 27, 2020
Deferred Tax Assets, Valuation Allowance, Total	$ 2,990,093	$ 3,381,133
Income Taxes Receivable	7,000,000		$ 1,500,000
Net Income (Loss) Attributable to Parent, Total	4,746,485	(6,074,952)
Income Tax Expense (Benefit), Total	28,377	(1,527,355)
Foreign Tax Authority [Member]
Income Tax Expense (Benefit), Total	121,000	(74,000)
CVD Tantaline ApS [Member] | DENMARK
Net Income (Loss) Attributable to Parent, Total	$ (552,000)	$ 336,000
CVD Tantaline ApS [Member] | DENMARK | Foreign Tax Authority [Member] | The Danish Ministry of Taxation [Member]
Effective Income Tax Rate Reconciliation, at Foreign Statutory Income Tax Rate, Percent	22.00%
Research [Member]
Tax Credit Carryforward, Amount	$ 1,671,893