CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Revenue	$ 457	$ 254
Cost of revenue	188	130
Gross profit	269	124
Operating expenses:
Research and development	12,101	18,167
Selling, general and administrative	11,528	11,178
Total operating expenses	23,629	29,345
Loss from operations	(23,360)	(29,221)
Dividend and interest income	3,574	2,219
Gain on marketable securities, net	0	2,942
Change in fair value of warrant liabilities	319	391
Other (expense) income, net	(7)	58
Loss before provision for income taxes	(19,474)	(23,611)
Provision for income taxes	0	0
Net loss	$ (19,474)	$ (23,611)
Net loss per common share attributable to common stockholders, basic (in dollars per share)	$ (0.14)	$ (0.17)
Net loss per common share attributable to common stockholders, diluted (in dollars per share)	$ (0.14)	$ (0.17)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic (in shares)	141,773	140,280
Weighted-average shares used to compute net loss per share attributable to common stockholders, diluted (in shares)	141,773	140,280
Other comprehensive loss:
Net unrealized loss on marketable securities, net of tax	$ (28)	$ 0
Foreign currency translation adjustment	(5)	0
Total other comprehensive loss, net of tax	(33)	0
Comprehensive loss	(19,507)	(23,611)
Product [Member]
Revenue:
Revenue	428	251
Service [Member]
Revenue:
Revenue	$ 29	$ 3