Note 8 - Stock-based Compensation Expense - Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock-based compensation	$ 262	$ 92	$ 397	$ 189
Cost of Revenue [Member]
Stock-based compensation	41	9	60	17
Research and Development Expense [Member]
Stock-based compensation	45	13	65	26
Selling and Shipping [Member]
Stock-based compensation	31	5	42	11
General and Administrative Expense [Member]
Stock-based compensation	$ 145	$ 65	$ 230	$ 135