Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities:
Net loss	$ (8,817)	$ (5,497)
Adjustments to reconcile net loss to net cash used in operating activities:
Bad debt expense	2	7
Inventory reserve	(144)	(4)
Depreciation and amortization	1,130	751
Stock-based compensation	1,010	787
Deferred taxes	(19)	(360)
Amortization of debt financing costs	90	46
Non-cash lease expense	47	106
Changes in operating assets and liabilities:
Accounts receivable	(518)	(1,319)
Inventories	240	(1,028)
Prepaid expenses and other current assets	271	(547)
Other non-current assets	102	(216)
Accounts payable	(386)	237
Accrued liabilities	(670)	762
Other	(22)	(20)
Cash used in operating activities	(7,684)	(5,201)
Investing activities:
Purchase of property, plant and equipment	(4,312)	(5,917)
Cash used in investing activities	(4,312)	(5,917)
Financing activities:
Payment of offering costs	(34)	0
Proceeds from exercise of stock options	9	55
Cash provided by financing activities	(25)	55
Change in cash and cash equivalents	(12,021)	(11,063)
Cash and cash equivalents at beginning of period	42,236	87,518
Cash and cash equivalents at end of period	30,215	76,455
Supplemental cash flow disclosures:
Income taxes paid	0	0
Interest paid	110	0
Capitalized property, plant and equipment included in accounts payable and accrued liabilities	925	3,884
Deferred offering costs included in accounts payable and accrued liabilities	329	0
Debt issuance costs included in accounts payable and accrued liabilities	30	0
Recognition of operating right-of-use lease asset	(648)	20,237
Recognition of operating lease liabilities	$ (602)	$ 20,507