stock-based compensation (Details Narrative) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 343,727	$ 347,185
Non-cash compensation expense	343,727	347,185
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	135,512
Non-cash compensation expense	284,000	258,000
Restricted Stock Units (RSUs) [Member] | Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	48,000	72,000
Restricted Stock Units (RSUs) [Member] | Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 11,000	$ 18,000