CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 308,000	$ 527,000
Cost of revenue	180,000	277,000
Gross profit	128,000	250,000
Research and development expenses	11,379,000	5,309,000
General and administrative expenses	8,217,000	1,304,000
Selling and marketing expenses	659,000	634,000
Operating loss	(20,127,000)	(6,997,000)
Interest income	3,000	162,000
Other income (expense), net	666,000	(17,000)
Loss before income taxes	(19,458,000)	(6,852,000)
Income taxes	0	0
Net loss	(19,458,000)	(6,852,000)
Unrealized loss on available-for-sale securities	(29,000)
Total comprehensive loss	$ (19,487,000)	$ (6,852,000)
Net loss per share, basic and diluted	$ (0.12)	$ (0.05)
Weighted-average shares used in computing net loss per share, basic and diluted	163,955,593	135,039,812