Note 13 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended
	December 31,
	2022			2021
U.S. federal statutory rate, beginning of year		21	%		21	%
Common stock warrant liabilities		(2	)		—
Officers' compensation		(1	)		—
Other		(1	)		(4	)
Valuation allowance		(17	)		(17	)
Effective tax rate as reported		—	%		—	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	Year Ended
	December 31,
	2022			2021
Deferred tax assets
Net operating loss carryforwards and credits	$	36,835		$	25,742
Employee compensation		1,113			570
Share-based compensation expense		1,066			2,053
Development costs		964			—
Property, plant and equipment		749			753
Operating lease liabilities		187			125
Other		36			55
Less: valuation allowance		(36,642	)		(26,378	)
Total deferred tax assets		4,308			2,920
Deferred tax liabilities
Operating lease right-of-use assets		(4,308	)		(2,920	)
Total deferred tax liabilities		(4,308	)		(2,920	)
Net deferred tax assets (liabilities)	$	—		$	—