Note 10 - Disaggregated Revenues and Segment Information - Net Revenue, Classified by Geography (Details) - USD ($)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net revenues	$ 3,018,954	$ 3,754,212
Chemical [Member]
Net revenues	1,318,814	1,391,522
Electronics [Member]
Net revenues	730,634	1,056,384
Engineering [Member]
Net revenues	969,506	1,306,306
UNITED STATES
Net revenues	2,654,536	3,412,797
UNITED STATES | Chemical [Member]
Net revenues	954,396	1,075,107
UNITED STATES | Electronics [Member]
Net revenues	730,634	1,031,384
UNITED STATES | Engineering [Member]
Net revenues	969,506	1,306,306
Non-US [Member]
Net revenues	364,418	341,415
Non-US [Member] | Chemical [Member]
Net revenues	364,418	316,415
Non-US [Member] | Electronics [Member]
Net revenues		25,000
Non-US [Member] | Engineering [Member]
Net revenues