Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Dec. 31, 2023	Jun. 30, 2023
Current assets
Cash and cash equivalents	$ 11,096	$ 14,208
Short-term investments	26,183	27,919
Accounts receivable	294	225
Inventory, net:
Raw materials	1,530	1,379
Work-in-process	275	243
Finished goods	260	373
Income tax receivable	0	1
Prepaid expenses and other current assets	426	365
Total current assets	40,064	44,713
Property and equipment, net	2,546	2,670
Operating lease assets	191	262
Other assets, net	30	30
Total assets	42,831	47,675
Current liabilities
Accounts payable	567	546
Payroll related accruals	817	633
Accrued expenses and other liabilities	621	1,170
Lease liabilities, current	309	316
Total current liabilities	2,314	2,665
Accrued expenses and other liabilities, net of current portion	91	0
Lease liabilities, net of current portion	152	291
Total liabilities	2,557	2,956
Commitments and contingencies (Note 13)
Stockholders’ equity
Convertible preferred stock, $0.001 par value, 2,500,000 shares authorized; 280,898 shares of Series D issued and outstanding at December 31, 2023 and June 30, 2023	0	0
Common stock, $0.001 par value, 250,000,000 shares authorized at December 31, 2023 and June 30, 2023, respectively; 1,712,045 and 1,692,045 shares issued at December 31, 2023 and June 30, 2023, respectively; 1,701,729 and 1,681,729 outstanding at December 31, 2023 and June 30, 2023, respectively	190,643	190,643
Treasury shares, 10,316 at December 31, 2023 and June 30, 2023, respectively	(119)	(119)
Additional paid-in capital	81,839	81,002
Accumulated deficit	(230,907)	(225,354)
Accumulated other comprehensive loss	(1,182)	(1,453)
Total stockholders’ equity	40,274	44,719
Total liabilities and stockholders’ equity	$ 42,831	$ 47,675