Fair value (Details 2) - Fair Value, Inputs, Level 3 [Member] - Fair Value, Measurements, Recurring [Member] - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Issuance of warrants and conversion options	$ 15,600	$ 57,800
Exchange of warrant for common stock	2,521	24,300
Extinguishment of conversion option	(1,000)
Warrant modification	283,500
Accrued compensation - warrants	50,760
Accrued compensation - warrants - related party	61,361	36,000
Change in fair value	(147,439)	(507,738)
Beginning balance	317,824	707,462
Ending balance	583,127	317,824
Accrued Compensation [Member]
Beginning balance	117,324	79,262
Issuance of warrants and conversion options
Exchange of warrant for common stock		24,300
Extinguishment of conversion option
Warrant modification
Accrued compensation - common stock	2,521
Accrued compensation - warrants	50,760
Accrued compensation - warrants - related party	61,361	36,000
Change in fair value	(739)	(22,238)
Ending balance	231,227	117,324
Derivative Financial Instruments, Liabilities [Member]
Issuance of warrants and conversion options		57,800
Exchange of warrant for common stock		57,800
Ending balance	351,900	200,500
Beginning balance	200,500	628,200
Accrued compensation - common stock
Accrued compensation - warrants
Accrued compensation - warrants - related party