Note 6 - Disaggregated Revenues and Segment Information - Summary of Segment Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 983,162	$ 749,654	$ 3,044,838	$ 2,322,871
Segment operating income (loss)	92,753	(416,172)	161,020	(1,011,743)
Total assets at December 31, 2022	3,207,822		3,207,822		$ 3,250,897
Chemical [Member]
Revenue from Contract with Customer, Including Assessed Tax	331,878	331,812	1,049,448	1,017,895
Segment operating income (loss)	23,137	(183,385)	35,548	(425,348)
Total assets at December 31, 2022	1,090,659		1,090,659		1,332,867
Electronics [Member]
Revenue from Contract with Customer, Including Assessed Tax	485,454	347,911	1,584,003	911,569
Segment operating income (loss)	18,034	(188,273)	(5,395)	(531,888)
Total assets at December 31, 2022	1,668,068		1,668,068		1,430,395
Engineering [Member]
Revenue from Contract with Customer, Including Assessed Tax	165,830	69,931	411,387	393,407
Segment operating income (loss)	51,582	$ (44,514)	130,867	$ (54,507)
Total assets at December 31, 2022	$ 449,095		$ 449,095		$ 487,635