Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Jun. 30, 2021
Current assets
Cash and cash equivalents	$ 26,453	$ 35,936
Short-term investments	26,173	27,351
Accounts receivable	56	5
Cost and estimated revenue in excess of billings	2	0
Inventory, net:
Raw materials	864	1,056
Work-in-process	136	147
Finished goods	518	297
Prepaid expenses and other current assets	748	318
Total current assets	54,950	65,110
Property and equipment, net	1,098	263
Operating lease assets	162	249
Other assets, net	11	11
Total assets	56,221	65,633
Current liabilities
Accounts payable	169	396
Payroll related accruals	816	344
Accrued expenses and other liabilities	961	888
Income tax payable	2	2
Term note payable - related party	500	2,500
Lease liabilities, current	234	81
Total current liabilities	2,682	4,211
Lease liabilities, net of current portion	303	215
Total liabilities	2,985	4,426
Commitments and contingencies (Note 14)
Stockholders’ equity
Convertible preferred stock, $0.001 par value, 2,500,000 shares authorized; 280,898 shares of Series D issued and outstanding at June 30, 2022 and 2021	0	0
Common stock, $0.001 par value, 250,000,000 and 50,000,000 shares authorized at June 30, 2022 and 2021 respectively; 50,567,864 and 49,450,558 shares issued and outstanding at June 30, 2022 and 2021, respectively	190,642	190,641
Additional paid-in capital	79,505	77,971
Accumulated deficit	(215,712)	(207,382)
Accumulated other comprehensive loss	(1,199)	(23)
Total stockholders’ equity	53,236	61,207
Total liabilities and stockholders’ equity	$ 56,221	$ 65,633