CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net loss	$ (37,647,000)	$ (42,825,000)	$ (54,376,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,599,000	2,984,000	3,148,000
Stock-based compensation	20,271,000	24,456,000	23,571,000
Non-cash operating lease cost	2,308,000	1,575,000	1,422,000
Changes in valuation of warrant investment		2,183,000	(148,000)
Loss (gain), net on sale of available-for-sale securities	54,000	108,000	(21,000)
Unrealized gain on investments	(170,000)	(564,000)	(267,000)
Impairment of long-lived assets			387,000
Loss on disposal of fixed assets	65,000
Impairment charges for facilities consolidation	1,698,000	0
Non-cash interest expense	374,000	609,000	591,000
Foreign currency remeasurement (gain) loss	(685,000)	1,911,000	511,000
Changes in operating assets and liabilities:
Accounts receivable	(1,102,000)	(9,200,000)	(4,215,000)
Inventories	(14,947,000)	(1,768,000)	(19,610,000)
Prepaid and other assets	(994,000)	1,168,000	2,738,000
Accounts payable	(7,335,000)	(4,905,000)	12,204,000
Accrued liabilities and other non-current liabilities	(9,070,000)	(1,263,000)	47,000
Deferred revenue	1,413,000	(84,000)	96,000
Net cash used in operating activities	(43,168,000)	(25,615,000)	(33,922,000)
Investing activities
Capital expenditures	(4,597,000)	(2,000,000)	(910,000)
Purchases of investments	(2,486,000)	(29,640,000)	(52,066,000)
Proceeds from maturities and sale of investments	15,707,000	40,104,000	65,664,000
Net cash provided by investing activities	8,624,000	8,464,000	12,688,000
Financing activities
Net proceeds from equity incentives	925,000	4,084,000	9,370,000
Net (costs) proceeds from public offerings	(175,000)	(104,000)	2,743,000
Net proceeds on revolving line of credit	5,091,000	212,000	6,181,000
Proceeds from loans, net of issuance costs	4,832,000		15,000,000
Contribution from noncontrolling interest	0		1,000,000
Net cash provided by financing activities	10,673,000	4,192,000	34,294,000
Effect of exchange rates on cash, cash equivalents, and restricted cash	(128,000)	(727,000)	(919,000)
Net (decrease) increase in cash, cash equivalents and restricted cash	(23,999,000)	(13,686,000)	12,141,000
Cash, cash equivalents and restricted cash, beginning of period	37,358,000	51,044,000	38,903,000
Cash, cash equivalents and restricted cash, end of period	13,359,000	37,358,000	51,044,000
Supplemental disclosure of cash flow information:
Cash paid for interest	9,210,000	5,100,000	4,181,000
Cash paid for income taxes	$ 322,000	$ 270,000	$ 278,000