4. BALANCE SHEET DETAIL - Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Prepaid expenses and other current assets:
Prepaid tooling and masks	$ 436	$ 68
Other receivables	249	226
Other prepaid expenses and other current assets	964	1,261
Total prepaid expenses and other current assets	$ 1,649	$ 1,555