Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Net loss	$ (15,836)	$ (18,114)
Adjustments to reconcile net loss to cash flows used in operating activities:
Depreciation and amortization	376	239
Stock-based compensation expense	1,349	1,512
Loss on disposal of property and equipment	40	0
Realized foreign currency translation gain from dissolution of subsidiary	(1,202)	0
Changes in operating assets and liabilities:
Accounts receivable	(106)	(13)
Inventories	(1,420)	(343)
Other current assets	(76)	42
Other assets and liabilities	112	18
Accounts payable and accrued compensation	191	292
Net cash used in operations	(16,572)	(16,367)
Investing activities:
Purchases of property and equipment	(298)	(490)
Proceeds from sale of property and equipment	31	0
Net cash used in investing activities	(267)	(490)
Financing activities:
Proceeds from public stock offerings, net	25,921	12,665
Proceeds from warrant exercises	4,115	0
Payments on finance lease liability	(20)	0
Net cash provided by financing activities	30,016	12,665
Effect of exchange rate changes on cash	(19)	(9)
Net increase (decrease) in cash and cash equivalents	13,158	(4,201)
Cash and cash equivalents - beginning of year	1,279	5,480
Cash and cash equivalents - end of year	14,437	1,279
Supplemental schedule of non-cash activities
Financing fees incurred for subsequent equity financing included in other assets and accounts payable	0	111
Inventory transferred to property, plant and equipment	260	204
Equipment acquired through finance lease liability	98	0
Supplemental cash flow information
Cash paid for income taxes	$ 10	$ 4