Note 9 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets, Valuation Allowance, Total	$ 2,497,414
Deferred Income Tax Assets, Net, Total		1,425,414
Retained Earnings (Accumulated Deficit), Ending Balance	3,172,054	9,499,712
Net Income (Loss) Attributable to Parent, Total	(6,327,658)	(5,201,021)
Deferred Tax Assets, Gross, Total	2,939,900	1,864,724
CVD Tantaline ApS [Member] | DENMARK
Net Income (Loss) Attributable to Parent, Total	(276,000)	(463,000)
Deferred Tax Assets, Gross, Total	$ 61,000	102,000
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%
Restatement Adjustment [Member]
Deferred Income Tax Assets, Net, Total		(679,000)
Retained Earnings (Accumulated Deficit), Ending Balance		$ (679,000)
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 588,000