Note 5 - Segment Information - Summary of Segment Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Chemical [Member]
Revenue from external customers	$ 363,364	$ 385,072	$ 654,848	$ 751,016
Segment operating income	102,390	(141,767)	101,215	59,133
Total assets	985,216		985,216		$ 1,070,944
Electronics [Member]
Revenue from external customers	370,450	202,374	937,073	377,603
Segment operating income	98,388	(62,222)	378,958	(46,554)
Total assets	1,409,822		1,409,822		644,189
Engineering [Member]
Revenue from external customers	646,524	665,435	1,165,848	1,180,190
Segment operating income	227,685	(143,926)	469,334	74,050
Total assets	1,754,016		1,754,016		1,707,413
Revenue from external customers	1,380,338	1,252,881	2,757,769	2,308,809
Segment operating income	428,463	$ (347,915)	949,507	$ 86,629
Total assets	$ 4,149,054		$ 4,149,054		$ 3,422,546