Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Operating activities:
Net loss	$ (12,501)	$ (21,026)
Adjustments to reconcile net loss to net cash used in operating activities:
Bad debt expense	71	61
Inventory reserve	1,657	4,235
Depreciation and amortization	4,761	4,933
Stock-based compensation	2,652	2,900
Deferred taxes	119	(52)
Accrued interest income on short-term investments	(8)	(118)
Amortization of discount on short-term investments	(508)	0
Amortization of debt financing costs	173	291
Other adjustment to loan exit fee	(485)	0
Non-cash lease expense	92	140
Loss on disposal of property, plant, and equipment	19	49
Changes in operating assets and liabilities:
Accounts receivable	(894)	(718)
Inventories	(1,770)	(315)
Prepaid expenses and other current assets	(1,464)	(943)
Other non-current assets	67	334
Accounts payable	244	(430)
Accrued liabilities	(399)	(724)
Other	(10)	(72)
Cash used in operating activities	(8,184)	(11,455)
Investing activities:
Purchases of short-term investments	(13,708)	(25,428)
Maturities of short-term investments	22,000	0
Proceeds from sale of property, plant, and equipment	0	125
Purchases of property, plant, and equipment	(800)	(558)
Cash provided by (used in) investing activities	7,492	(25,861)
Financing activities:
Proceeds from equity financing, net	0	15,104
Proceeds from long-term debt	1,110	0
Payment of exit fee costs	(1,110)	0
Proceeds from financed insurance premiums	333	385
Repayment of financed insurance premiums	(150)	(572)
Proceeds from exercise of stock options	49	4
Proceeds from issuance of common stock under employee stock purchase plan	56	81
Payment of debt issuance costs	(100)	(25)
Cash provided by financing activities	188	14,977
Change in cash and cash equivalents	(504)	(22,339)
Cash and cash equivalents at beginning of period	3,708	28,484
Cash and cash equivalents at end of period	3,204	6,145
Supplemental cash flow disclosures:
Income taxes paid	44	41
Interest paid, net of amounts capitalized	1,098	1,178
Offering costs included in accounts payable and accrued liabilities	0	18
Capitalized property, plant, and equipment included in accounts payable and accrued liabilities	93	90
Issuance of common stock warrants	0	132
Recognition of operating right-of-use lease asset	564	1,293
Recognition of operating lease liabilities	$ 564	$ 1,306