Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (1,577)	$ (7,656)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,671	1,427
Change in fair value of common stock warrant liability	(1,372)	4,566
Gain on forgiveness of debt		(1,963)
Stock-based compensation	379	50
Amortization of operating lease right-of-use assets	29	30
Changes in operating assets and liabilities:
Accounts receivable	(607)	3,133
Unbilled accounts receivable	(216)	(530)
Inventories	(29)	246
Prepaid expenses and other current assets	19	148
Deferred revenues	60	(339)
Operating lease liabilities	(29)	(30)
Accounts payable, accrued expenses, and other current liabilities	(173)	(1,134)
Net cash used in operating activities	(1,845)	(2,052)
Cash flows from investing activities:
Purchase of equipment	(1,128)	(501)
Purchase of equipment, government grant	(7,418)	(5,198)
Net cash used in investing activities	(8,546)	(5,699)
Cash flows from financing activities:
Borrowings (repayments) under revolving line of credit, net	113	(1,470)
Proceeds from public offering, net	2,060
Change in finance lease liabilities	(144)	(158)
Proceeds from government grant	6,633	4,615
Proceeds from warrant exercise		5,652
Proceeds from exercise of stock options		745
Net cash provided by financing activities	8,662	9,384
Net (decrease) increase in cash, cash equivalents, and restricted cash	(1,729)	1,633
Cash, cash equivalents, and restricted cash, beginning of period	6,530	10,426
Cash, cash equivalents, and restricted cash, end of period	4,801	12,059
Cash, cash equivalents, end of period	4,290	10,568
Restricted cash, end of period	511	1,491
Supplementary Cash Flow Information
Cash paid for interest	439	210
Cash paid for income taxes
Non-cash activities:
Right-of-use assets obtained in exchange for finance lease liabilities	$ 137	$ 108