Note 9 - Stock-based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

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

	Three months ended September 30,				Nine months ended September 30,
	2022		2021		2022		2021
Cost of revenue	$	9,221	$	7,715	$	26,100	$	7,715
Research and development		16,367		3,972		42,684		3,972
Selling and shipping		7,508		4,371		18,305		4,371
General and administrative		85,452		89,433		220,290		201,884
Total	$	118,548	$	105,491	$	307,379	$	217,942

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

2007 Share Incentive Plan
	Beginning		Granted		Exercised		Canceled			Ending
	Balance		During		During		During			Balance
	Outstanding		Period		Period		Period			Outstanding		Exercisable
Number of shares		220,000		-		-		(75,000	)		145,000		145,000
Weighted average exercise price per share	$	12.56		-		-	$	15.00		$	11.29	$	11.29

2016 Equity Incentive Plan
	Beginning		Granted		Exercised		Canceled			Ending
	Balance		During		During		During			Balance
	Outstanding		Period		Period		Period			Outstanding		Exercisable
Number of shares		398,500		102,500		-		(44,000	)		457,000		145,500
Weighted average exercise price per share	$	4.43	$	4.97		-	$	4.25		$	4.56	$	4.94

2022 Equity Incentive Plan
	Beginning		Granted		Exercised		Canceled		Ending
	Balance		During		During		During		Balance
	Outstanding		Period		Period		Period		Outstanding		Exercisable
Number of shares		-		76,000		-		-		76,000		-
Weighted average exercise price per share		-	$	5.13		-		-	$	5.13		-

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

Stock Price	$	5.04
Exercise Price	$	5.04
Dividend yield		0	%
Expected volatility		68	%
Risk-Free interest rate		2.96	%
Expected life (in years)		6.00

Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

			Options Outstanding								Options Exercisable
					Weighted		Weighted						Weighted
					Average		Average						Average
Exercise			Number		Remaining		Exercise		Intrinsic		Number		Exercise		Intrinsic
Price Range			Outstanding		Contractual		Price		Value		Exercisable		Price		Value
$4.00	-	7.00		513,000		8.8	$	4.51	$	249,645		125,500	$	4.94	$	67,905
$7.01	-	10.00		20,000		5.6	$	8.07	$	0		20,000	$	8.07	$	0
$10.01	-	12.00		120,000		4.5	$	10.52	$	0		120,000	$	10.52	$	0
$12.01	-	15.00		25,000		.1	$	15.00	$	0		25,000	$	15.00	$	0

Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

				Weighted
	Shares of			Average Grant
	Restricted			Date Fair
	Stock Units			Value
Unvested outstanding at December 31, 2021		5,500		$	4.82
Granted		-		$	-
Vested		(5,500	)	$	4.82
Forfeited or cancelled		-		$	-
Unvested outstanding at September 30, 2022		-		$	-