Note 3 - Revenue From Contracts With Customers (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Payment Term, Minimum (Day)	15 days
Contract with Customer, Payment Term, Maximum (Day)	90 days
Contract with Customer, Transaction Price of Royalties Using Expected Value Method	$ 0
Revenue from Contract with Customer, Including Assessed Tax	119,000	$ 38,000
Contract with Customer, Asset, Impairment Loss	0	0
Capitalized Contract Cost, Net, Total	0
Contract with Customer, Asset, after Allowance for Credit Loss, Total	59,000	0
Grant [Member]
Revenue Not from Contract with Customer	$ 696,000	$ 611,000
INDIA
Contract with Customer, Term of Contract (Year)	8 years
CHINA
Contract with Customer, Term of Contract (Year)	10 years