Note 7 - Disaggregated Revenues and Segment Information - Summary of Segment Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Revenue from external customers	$ 749,654	$ 762,644	$ 2,322,871	$ 2,258,822
Segment operating (loss)	(416,172)	(76,721)	(1,011,743)	(255,225)
Segment operating (loss)	(416,172)	(76,721)	(1,011,743)	(255,225)
Total assets	4,474,089		4,474,089		$ 5,214,099
Chemical [Member]
Revenue from external customers	331,812	352,484	1,017,895	949,574
Segment operating (loss)	(191,075)	(14,585)	(425,348)	(70,895)
Segment operating (loss)	(191,075)	(14,585)	(425,348)	(70,895)
Total assets	1,968,599		1,968,599		2,033,499
Electronics [Member]
Revenue from external customers	347,911	270,245	911,569	955,217
Segment operating (loss)	(186,112)	(83,033)	(531,891)	(259,137)
Segment operating (loss)	(186,112)	(83,033)	(531,891)	(259,137)
Total assets	1,744,895		1,744,895		2,294,203
Engineering [Member]
Revenue from external customers	69,931	139,915	393,407	354,031
Segment operating (loss)	(38,985)	20,897	(54,504)	74,807
Segment operating (loss)	(38,985)	$ 20,897	(54,504)	$ 74,807
Total assets	$ 760,595		$ 760,595		$ 886,397