| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Jun-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| ASSETS | | | | | | | | |
| Current Assets: | | | | | | | | |
| Cash and cash equivalents | 0.9 | 6.3 | 11.5 | 2.9 | 0.4 | 3.0 | 6.0 | 1.4 |
| Trade receivables, net of allowance of $0 and $26,000, respectively | 0.0 | 0.1 | 0.0 | 0.1 | 0.8 | 0.6 | 0.0 | |
| Inventories, net | 0.7 | 0.5 | 0.6 | 0.7 | 0.7 | 0.6 | 0.6 | 0.6 |
| Prepaid and other current assets | 0.3 | 1.5 | 0.3 | 0.9 | 0.8 | 0.7 | 0.2 | 0.5 |
| Total current assets | 1.9 | 8.5 | 12.4 | 4.5 | 2.8 | 4.9 | 6.9 | 2.5 |
| Property, Plant and Equipment: | 26.4 | 22.6 | 22.6 | 22.6 | 22.7 | 22.5 | 22.4 | 25.0 |
| Accumulated depreciation | -22.1 | -22.1 | -22.0 | -22.0 | -22.2 | -22.2 | -22.1 | -24.9 |
| Property, Plant and Equipment, net | 4.4 | 0.6 | 0.6 | 0.5 | 0.5 | 0.3 | 0.3 | 0.1 |
| |
| Other Assets: | | | | | | | | |
| Operating lease right-of-use assets, net | 3.9 | 4.1 | 4.3 | 4.5 | 4.7 | 4.8 | 5.0 | 5.3 |
| Patents, net of accumulated amortization of $163,803 and $154,218respectively | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.4 |
| Equity method investment | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.0 | |
| Other non-current assets | 6.7 | 6.8 | 6.9 | 0.6 | 0.6 | 0.6 | 6.3 | 0.6 |
| Total other assets | 6.7 | 6.8 | 6.9 | 0.6 | 0.6 | 0.6 | 6.3 | 0.6 |
| Total Assets | 11.7 | 14.6 | 18.7 | 10.3 | 8.8 | 10.8 | 12.8 | 8.9 |
| |
| LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT) | | | | | | | | |
| Current Liabilities: | | | | | | | | |
| Accounts payable | 1.2 | 0.6 | 0.6 | 0.7 | 0.8 | 0.6 | 0.6 | 0.7 |
| Related party payables | 0.0 | | | | | | | |
| Accrued expenses | 1.3 | 1.9 | 1.0 | 2.3 | 1.5 | 1.4 | 0.7 | 0.8 |
| Accrued payroll | 0.5 | 0.8 | | | | | | |
| Accrued professional services fees | 0.8 | 1.2 | 1.0 | | | | 0.1 | |
| Accrued interest | 0.7 | 0.7 | 0.6 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Current portion of operating lease liability | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 | 0.6 |
| Conversions payable | 0.5 | | | | | | | |
| Current portion of convertible notes, net | 5.6 | 2.0 | | | 1.0 | 0.9 | | 0.3 |
| Other payable | 0.3 | 0.3 | 0.3 | | | | 0.3 | |
| Total current liabilities | 11.0 | 7.0 | 5.0 | 4.6 | 3.8 | 3.4 | 3.1 | 3.2 |
| |
| Long-Term Liabilities: | | | | | | | | |
| Non-current operating lease liabilities | 3.4 | 3.6 | 3.8 | 4.0 | 4.2 | 4.4 | 4.5 | 4.9 |
| Non-current convertible notes, net | 0.5 | 6.1 | 5.3 | | 1.0 | 0.9 | 8.1 | 7.9 |
| Accrued warranty liability | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Total liabilities | 14.5 | 16.7 | 14.1 | 8.6 | 9.0 | 8.8 | 15.7 | 16.0 |
| |
| Commitments and contingencies (Note 14) | | | | | | | | |
| Stockholders’ Equity (Deficit): | | | | | | | | |
| Series A preferred stock, $.0001 par value; 750,000 shares authorized; 48,100 and 48,100 shares issued and outstanding, respectively | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Common stock | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.8 |
| Additional paid in capital | 466.3 | 451.3 | 452.1 | 444.0 | 434.1 | 434.1 | 424.9 | 412.7 |
| Accumulated deficit | -469.1 | -453.5 | -447.5 | -442.3 | -434.4 | -432.1 | -427.8 | -421.6 |
| Accumulated other comprehensive loss | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | | |
| Total stockholders’ equity (deficit) | -2.8 | -2.2 | 4.6 | 1.7 | -0.3 | 2.1 | -2.8 | -7.1 |
| Total Liabilities and Stockholders’ Equity (Deficit) | 11.7 | 14.6 | 18.7 | 10.3 | 8.8 | 10.8 | 12.8 | 8.9 |