Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
REVENUE:
Total revenue	$ 636	$ 1,082
Cost of revenue	2,261	1,482
Gross loss	(1,625)	(400)
OPERATING EXPENSES:
Research and development	9,442	8,576
Sales and marketing	6,268	4,616
General and administrative	8,554	11,330
Total operating expenses	24,264	24,522
LOSS FROM OPERATIONS	(25,889)	(24,922)
OTHER INCOME (EXPENSE):
Change in fair value of convertible note and warrant liabilities	(810)	(32)
Interest income and other	277	424
Interest expense and other	176	(343)
Total other income (expense), net	(357)	49
Provision for income tax expense	19	8
Net loss	$ (26,265)	$ (24,881)
PER SHARE DATA
Net loss per common share (basic) (in dollars per share)	$ (0.16)	$ (0.16)
Net loss per common share (diluted) (in dollars per share)	$ (0.16)	$ (0.16)
Weighted average common shares outstanding (basic) (in shares)	165,865,864	155,515,093
Weighted average common shares outstanding (diluted) (in shares)	165,865,864	155,515,093
COMPREHENSIVE LOSS:
Net loss	$ (26,265)	$ (24,881)
Change in net unrealized loss on available-for-sale securities, net of tax	490	(1,056)
Change in fair value due to instrument-specific credit risk, net of tax	(21)	0
Comprehensive loss	(25,796)	(25,937)
Prototype sales
REVENUE:
Total revenue	125	335
Development contracts
REVENUE:
Total revenue	$ 511	$ 747