Note 6 - Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Revenues	$ 477	$ 599	$ 1,091	$ 1,112
Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
JAPAN
Revenues	$ 229	$ 262	$ 659	$ 612
JAPAN \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	48.00%	43.60%	60.40%	55.00%
SWEDEN
Revenues	$ 149	$ 204	$ 206	$ 237
SWEDEN \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	31.20%	34.10%	18.90%	21.30%
GERMANY
Revenues	$ 6	$ 13	$ 13	$ 23
GERMANY \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	1.30%	2.20%	1.20%	2.10%
CHINA
Revenues	$ 0	$ 4	$ 1	$ 10
CHINA \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	0.00%	0.70%	0.10%	0.90%
KOREA, REPUBLIC OF
Revenues	$ 0	$ 1	$ 0	$ 1
KOREA, REPUBLIC OF \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	0.00%	0.20%	0.00%	0.10%
Non-US [Member]
Revenues	$ 384	$ 484	$ 879	$ 884
Non-US [Member] \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	80.50%	80.80%	80.60%	79.50%
Other Foreign Countries [Member]
Revenues			$ 0	$ 1
Other Foreign Countries [Member] \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage			0.00%	0.10%
UNITED STATES
Revenues	$ 93	$ 115	$ 212	$ 228
UNITED STATES \| Geographic Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	19.50%	19.20%	19.40%	20.50%