Note 10 - Segment Information - Summary of Segment Information (Details) - USD ($)	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue	$ 3,676,785	$ 3,206,594
Segment operating (loss)	30,335	(1,129,314)
Total assets	3,089,825	3,349,663
Chemical [Member]
Revenue	1,258,890	1,319,578
Segment operating (loss)	(49,966)	(443,587)
Total assets	1,050,541	1,365,789
Electronics [Member]
Revenue	1,883,251	1,405,594
Segment operating (loss)	(65,271)	(662,808)
Total assets	1,575,811	1,463,317
Engineering [Member]
Revenue	534,644	481,422
Segment operating (loss)	145,572	(22,919)
Total assets	$ 463,473	$ 520,557