Note 7 - Disaggregated Revenues and Segment Information - Summary of Segment Information (Details) - USD ($)	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020
Revenue from Contract with Customer, Including Assessed Tax	$ 569,093	$ 830,821
Segment operating (loss)	(183,870)	69,285
Total assets	5,287,302		$ 5,053,089
Chemical [Member]
Revenue from Contract with Customer, Including Assessed Tax	186,523	387,632
Segment operating (loss)	(45,152)	74,901
Total assets	1,732,939		2,021,235
Electronics [Member]
Revenue from Contract with Customer, Including Assessed Tax	288,062	154,767
Segment operating (loss)	(114,805)	(56,860)
Total assets	2,676,313		1,970,705
Engineering [Member]
Revenue from Contract with Customer, Including Assessed Tax	94,508	288,422
Segment operating (loss)	(23,913)	$ 51,244
Total assets	$ 878,050		$ 1,061,149