Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (1,113)	$ (839)	$ (1,153)	$ (1,837)
Adjustments to reconcile net loss to net cash used in operating activities
Loss on disposition of Tantaline	162	0	162	0
Impairment charge	111	0	111	0
Stock-based compensation			397	189
Depreciation and amortization	227	151	392	402
Changes in assets and liabilities, net of effects of disposition of Tantaline:
Accounts receivable			1,592	(1,126)
Contract assets			(781)	(1,717)
Inventories			(1,616)	(825)
Tax receivable			0	716
Other current assets			231	(35)
Accounts payable			(57)	261
Accrued expenses			(770)	98
Contract liabilities			659	1,645
Net cash used in operating activities			(833)	(2,229)
Cash flows from investing activities:
Net cash used in connection with disposition of Tantaline			(312)	0
Purchases of property and equipment	(78)	(283)	(225)	(460)
Capitalized patent costs			0	(47)
Net proceeds from sale of assets			0	10
Net cash used in investing activities			(537)	(497)
Cash flows from financing activities
Proceeds from exercise of stock options			76	0
Payments of long-term debt			(38)	(1,766)
Net cash provided by (used in) financing activities			38	(1,766)
Net decrease in cash and cash equivalents			(1,332)	(4,492)
Cash and cash equivalents at beginning of period			14,365	16,651
Cash and cash equivalents at end of period	$ 13,033	$ 12,159	13,033	12,159
Supplemental disclosure of cash flow information:
Income taxes paid			11	0
Interest paid			$ 12	$ 8