Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (6,579)	$ (4,187)	$ (17,909)	$ (15,283)
Adjustments to reconcile net loss to net cash used in operating activities:
Inventory write-off	7	169	435	155
Depreciation and amortization	197	236	835	1,216
(Recovery from) provision for doubtful accounts	(48)	0	110	0
Licensing revenue from a related party	0	0	(5,000)	0
Stock-based compensation	513	132	1,525	566
Interest cost	187	189	760	608
Gain on sale of equipment	(40)	0	0	0
Loss in joint venture	1,468	1,419	6,836	3,703
Changes in fair value of promissory note	699	(2,321)	(927)	167
Changes in operating assets and liabilities:
Accounts receivable	(690)	(668)	(245)	(429)
Inventory	(603)	(264)	(1,072)	(293)
Prepaid expenses and other current assets	108	(603)	(283)	(154)
Other assets	17	9	206	(42)
Accounts payable and accrued expenses	(195)	(179)	(116)	509
Deferred revenue	(169)	0	674	(3,000)
Accrued payroll and benefits	195	(83)	56	(13)
Net cash used in operating activities	(4,933)	(6,151)	(14,115)	(12,290)
Cash flows from investing activities:
Purchases of property and equipment	(164)	0	(58)	(203)
Investment in joint venture	(968)	(1,548)	(7,348)	(2,698)
Net cash used in investing activities	(1,132)	(1,548)	(7,406)	(2,901)
Cash flows from financing activities:
Proceeds from sale of equipment	4	0	0	0
Proceeds from development loans	0	0	0	15,000
Proceeds from stock option exercise	2	18	32	0
Payment for repurchase of common stock	0	(211)	(211)	0
Loan repayment	0	(50)	(50)	0
Proceeds from issuance of common stock, net of offering cost	950	19,741	33,387	0
Net cash provided by financing activities	956	19,498	33,158	15,000
Effect of foreign exchange rate changes on cash and cash equivalents	(85)	(26)	182	(3)
Net (decrease) increase in cash and cash equivalents	(5,194)	11,773	11,819	(194)
Cash and cash equivalents at beginning of period	14,694	2,875	2,875	3,069
Cash and cash equivalents at end of period	9,500	14,648	14,694	2,875
Supplemental disclosures of cash flow information:
Interest expense paid	153	0	915	496
Supplemental non-cash financing activity:
Private placement offering cost	0	0	223	177
Development loan reduction related to licensing revenue	0	0	5,000	0
Conversion of preferred stock to common stock in connection with the Reverse Merger	$ 0	$ 85,658	$ 85,658	$ 0