Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2019	Mar. 31, 2018
Provision for Doubtful Accounts		$ 0	$ 0
Allowance for Doubtful Accounts Receivable, Write-offs		$ 0	0
Product Warranty Term		1 year
Impairment of Long-Lived Assets Held-for-use		$ 0	0
Depreciation, Depletion and Amortization, Nonproduction, Total		$ 498,813	$ 692,665
Accounting Standards Update 2018-02 [Member]
Tax Cuts and Jobs Act of 2017 Reclassification from AOCI to Retained Earnings Tax Effect	$ 60,365
Machinery and Equipment [Member]
Property, Plant and Equipment, Useful Life		5 years
Leasehold Improvements [Member]
Property, Plant and Equipment, Useful Life		5 years