Note 9 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net Income (Loss) Attributable to Parent, Total	$ (1,392,730)	$ (1,330,526)	$ (3,569,676)	$ (772,122)
CVD Tantaline ApS [Member] | DENMARK
Net Income (Loss) Attributable to Parent, Total			134,000	394,000
Deferred Tax Assets, Gross, Total	$ 28,000	$ 83,000	$ 28,000	$ 83,000
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%		22.00%