Condensed Statements of Changes in Stockholders' Deficit - USD ($)	Common stock [Member]	Additional paid-in capital [Member]	Accumulated deficit [Member]	Total
Balance at Dec. 31, 2019	$ 131,507	$ 104,896,975	$ (107,368,590)	$ (2,340,108)
Balance (Shares) at Dec. 31, 2019	131,506,494
Issuance of common stock - warrant exercises (in value)	$ 1,935	239,976	0	241,911
Issuance of common stock - warrant exercises (in shares)	1,935,294
Stock-based compensation expense	$ 0	49,839	0	49,839
Net loss	0	0	(386,733)	(386,733)
Balance at Mar. 31, 2020	$ 133,442	105,186,790	(107,755,323)	(2,435,091)
Balance (Shares) at Mar. 31, 2020	133,441,788
Balance at Dec. 31, 2019	$ 131,507	104,896,975	(107,368,590)	(2,340,108)
Balance (Shares) at Dec. 31, 2019	131,506,494
Net loss				(1,155,493)
Balance at Sep. 30, 2020	$ 133,442	105,407,209	(108,524,083)	(2,983,432)
Balance (Shares) at Sep. 30, 2020	133,441,788
Balance at Mar. 31, 2020	$ 133,442	105,186,790	(107,755,323)	(2,435,091)
Balance (Shares) at Mar. 31, 2020	133,441,788
Stock-based compensation expense	$ 0	146,433	0	146,433
Net loss	0	0	(436,161)	(436,161)
Balance at Jun. 30, 2020	$ 133,442	105,333,223	(108,191,484)	(2,724,819)
Balance (Shares) at Jun. 30, 2020	133,441,788
Stock-based compensation expense	$ 0	73,986	0	73,986
Net loss	0	0	(332,599)	(332,599)
Balance at Sep. 30, 2020	$ 133,442	105,407,209	(108,524,083)	(2,983,432)
Balance (Shares) at Sep. 30, 2020	133,441,788
Balance at Dec. 31, 2020	$ 133,442	105,934,572	(108,891,958)	(2,823,944)
Balance (Shares) at Dec. 31, 2020	133,441,788
Issuance of common stock - option exercises (in value)	$ 105	21,945	0	22,050
Issuance of common stock - option exercises (in shares)	105,000
Stock-based compensation expense	$ 0	61,744	0	61,744
Net loss	0	0	(379,692)	(379,692)
Balance at Mar. 31, 2021	$ 133,547	106,018,261	(109,271,650)	(3,119,842)
Balance (Shares) at Mar. 31, 2021	133,546,788
Balance at Dec. 31, 2020	$ 133,442	105,934,572	(108,891,958)	$ (2,823,944)
Balance (Shares) at Dec. 31, 2020	133,441,788
Issuance of common stock - option exercises (in shares)				105,000
Net loss				$ (1,148,170)
Balance at Sep. 30, 2021	$ 143,550	108,027,910	(110,040,128)	(1,868,668)
Balance (Shares) at Sep. 30, 2021	143,549,735
Balance at Mar. 31, 2021	$ 133,547	106,018,261	(109,271,650)	(3,119,842)
Balance (Shares) at Mar. 31, 2021	133,546,788
Private offering of common stock and warrants, net of issuance costs (in value)	$ 9,900	1,833,600	0	1,843,500
Private offering of common stock and warrants, net of issuance costs (in Shares)	9,900,000
Stock-based compensation expense	$ 0	61,744	0	61,744
Net loss	0	0	(338,633)	(338,633)
Balance at Jun. 30, 2021	$ 143,447	107,913,605	(109,610,283)	(1,553,231)
Balance (Shares) at Jun. 30, 2021	143,446,788
Issuance of common stock - warrant exercises (in value)	$ 103	12,765	0	12,868
Issuance of common stock - warrant exercises (in shares)	102,947
Private offering - issuance costs	$ 0	(84,412)	0	(84,412)
Stock-based compensation expense	0	185,952	0	185,952
Net loss	0	0	(429,845)	(429,845)
Balance at Sep. 30, 2021	$ 143,550	$ 108,027,910	$ (110,040,128)	$ (1,868,668)
Balance (Shares) at Sep. 30, 2021	143,549,735