Note 7 - Disaggregated Revenues and Segment Information - Summary of Segment Information (Details) - USD ($)	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021
Revenue from Contract with Customer, Including Assessed Tax	$ 721,358	$ 569,093
Segment operating income (loss)	(42,997)	(183,870)
Net revenues	721,358	569,093
Segment operating (loss)	(42,997)	(183,870)
Total assets	5,074,702		$ 5,214,099
Chemical [Member]
Revenue from Contract with Customer, Including Assessed Tax	315,257	186,523
Segment operating income (loss)	(11,107)	(45,152)
Net revenues	315,257	186,523
Segment operating (loss)	(11,107)	(45,152)
Total assets	2,217,811		2,033,499
Electronics [Member]
Revenue from Contract with Customer, Including Assessed Tax	222,574	288,062
Segment operating income (loss)	(93,473)	(114,805)
Net revenues	222,574	288,062
Segment operating (loss)	(93,473)	(114,805)
Total assets	1,565,792		2,294,203
Engineering [Member]
Revenue from Contract with Customer, Including Assessed Tax	183,527	94,508
Segment operating income (loss)	61,583	(23,913)
Net revenues	183,527	94,508
Segment operating (loss)	61,583	$ (23,913)
Total assets	$ 1,291,099		$ 886,397