Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Total revenue	$ 2,500	$ 3,090	$ 8,886
Total cost of revenue	2	1,398	8,564
Gross profit	2,498	1,692	322
Research and development expense	24,111	9,840	18,661
Sales, marketing, general and administrative expense	22,256	5,917	8,133
Gain on disposal of fixed assets		(450)
Total operating expenses	46,367	15,307	26,794
Loss from operations	(43,869)	(13,615)	(26,472)
Gain on debt extinguishment	692
Other expenses, net	(23)	(19)	(11)
Net loss	$ (43,200)	$ (13,634)	$ (26,483)
Net loss per share - basic and diluted	$ (0.27)	$ (0.10)	$ (0.24)
Weighted-average shares outstanding - basic and diluted	160,662	139,829	111,297