Note 7 - Stockholders' Equity (Tables)

12 Months Ended

Jun. 30, 2021

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Weighted Average, June 30, 2021			Range, June 30, 2021				Weighted Average, June 30, 2020			Range, June 30, 2020
Volatility		65	%		58%	-	65%		61	%		60%	-	70%
Dividend yield		—				—			—				—
Risk-free interest rate		0.79	%		0.47%	–	0.82%		0.60	%		0.36%	-	1.75%
Expected term (years)		5.8			5.0	to	5.9		4.8			4.7	to	5.2

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at July 1, 2019		7,411,600		$	1.08		3.1	$	20,375
Granted		2,210,000			0.72
Exercised		-			-
Forfeited		-			-
Expired		(110,000	)		0.69
Outstanding at June 30, 2020		9,511,600		$	0.74		4.5	$	-
Granted		960,000			1.10
Exercised		-			-
Forfeited		-			-
Expired		-			-
Outstanding at June 30, 2021		10,471,600		$	0.77		3.7	$	6,064,335
Exercisable at June 30, 2021		10,471,600		$	0.77		3.7	$	6,064,335

Schedule of Nonvested Share Activity [Table Text Block]

	Options			Weighted Average Grant-Date Fair Value
Nonvested at July 1, 2020		-		$	-
Granted		960,000			1.06
Vested		(960,000	)		(1.06	)
Nonvested at June 30, 2021		—		$	—

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year ended June 30, 2021		Year ended June 30, 2020
General and administrative:
Change in fair value from modification of option terms	$	8,775	$	511,448
Change in fair value from modification of warrant terms		25,506		1,064,503
Fair value of stock options expensed		816,050		355,100
Total	$	850,331	$	1,931,051
Research and development:
Change in fair value from modification of option terms	$	-	$	114,610
Change in fair value from modification of warrant terms		-		457,273
Fair value of stock options expensed		201,650		74,100
Total	$	201,650	$	645,983