Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Dec. 31, 2024	Jun. 30, 2024
Current assets
Cash and cash equivalents	$ 3,161,000	$ 10,442,000
Short-term investments	21,531,000	21,474,000
Accounts receivable	340,000	77,000
Contract Asset	4,000	0
Inventory, net:
Raw materials	2,121,000	2,038,000
Work-in-process	181,000	66,000
Finished goods	347,000	370,000
Prepaid expenses and other current assets	478,000	261,000
Total current assets	28,163,000	34,728,000
Property, Plant and Equipment, Net	2,760,000	2,763,000
Operating lease assets	48,000	119,000
Other assets, net	30,000	30,000
Total assets	31,001,000	37,640,000
Liabilities, Current [Abstract]
Accounts payable	1,032,000	373,000
Payroll related accruals	923,000	1,174,000
Accrued expenses and other liabilities	587,000	754,000
Operating and Finance Leases, Liability, Current	81,000	227,000
Total current liabilities	2,623,000	2,528,000
Accrued expenses and other liabilities, net of current portion	223,000	232,000
Operating and Finance Leases, Liability, Noncurrent	61,000	73,000
Total liabilities	2,907,000	2,833,000
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, 2024 and June 30, 2024, respectively	0	0
Common stock, $0.001 par value, 250,000,000 shares authorized at December 31, 2024, and June 30, 2024, respectively; 1,712,045 shares issued at December 31, 2024, and June 30, 2024, respectively; 1,701,729 outstanding at December 31, 2024, and June 30, 2024, respectively	190,643,000	190,643,000
Treasury shares, 10,316 at December 31, 2024, and June 30, 2024, respectively	(119,000)	(119,000)
Additional paid-in capital	82,957,000	82,480,000
Accumulated deficit	(244,307,000)	(237,020,000)
Accumulated other comprehensive loss	(1,080,000)	(1,177,000)
Total stockholders’ equity	28,094,000	34,807,000
Total liabilities and stockholders’ equity	$ 31,001,000	$ 37,640,000