Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 21,669	$ 6,329
Short-term investments, available-for-sale	11,420	64,195
Accounts receivable, net	662	2,256
Inventory, net	6,683	8,284
Prepaid expenses	4,174	3,584
Employee retention tax credit receivable	0	554
Other current assets	1,324	1,671
Total Current Assets	45,932	86,873
Restricted cash	1,615	1,141
Long-term investments, available-for-sale	0	3,865
Inventory, net of current portion	5,640	5,469
Property and equipment, net	9,237	9,542
Intellectual property, net	1,278	1,576
Deferred tax assets, net	150	174
Operating lease right-of-use assets, net	5,004	4,950
Other noncurrent assets	1,871	2,463
Total Assets	70,727	116,053
Current Liabilities:
Accounts payable	4,526	3,348
Accrued employee compensation and benefits	4,967	4,508
Accrued expenses and other current liabilities	1,258	1,293
Operating lease liabilities, current	916	800
Deferred revenue	456	465
Total Current Liabilities	12,123	10,414
Long-Term Liabilities:
Warrant liabilities	4,842	0
Contingent consideration	1,930	1,256
Operating lease liabilities, noncurrent	4,579	4,738
Total Liabilities	23,474	16,408
Stockholders' Equity:
Common stock $0.001 par value, 750,000,000 shares authorized at September 30, 2023 and December 31, 2022; 264,111,257 and 236,895,440 issued and outstanding at September 30, 2023 and December 31, 2022, respectively	264	237
Preferred stock, $0.01 par value, 25,000,000 shares authorized, no shares issued and outstanding at September 30, 2023 and December 31, 2022	0	0
Additional paid-in capital	970,952	962,731
Accumulated deficit	(922,133)	(860,935)
Accumulated other comprehensive loss	(1,830)	(2,388)
Total Stockholders' Equity	47,253	99,645
Total Liabilities and Stockholders' Equity	70,727	116,053
Intellectual Property [Member]
Current Assets:
Intellectual property, net	$ 1,278	$ 1,576