Annual report pursuant to Section 13 and 15(d)

Share-based compensation - Underwriters Warrants (Details)

v3.22.4
Share-based compensation - Underwriters Warrants (Details) - USD ($)
 12 Months Ended
Sep. 19, 2022
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 21, 2021
Share-based compensation          
Warrants to purchase shares 500,000       172,500
Warrants exercise price $ 0.625       $ 12.50
Remaining contractual term 5 years       5 years
Aggregate grant date fair value $ 178,462        
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]          
Discount rates 3.69%        
Expected life 5 years        
Expected volatility 96.46%        
Expected dividends $ 0        
Share price $ 0.50        
Unrecognized compensation expense   $ 0      
Number of Shares          
Warrants outstanding at the beginning of the period   172,500 172,500    
Warrants granted   500,000      
Warrants outstanding at the end of the period   672,500 172,500 172,500  
Exercisable at December 31, 2022   172,500      
Weighted Average Exercise Price          
Outstanding at the beginning of the period   $ 12.50 $ 12.50    
Granted   0.63      
Outstanding at the end of the period   3.67 $ 12.50 $ 12.50  
Exercisable at December 31, 2022   $ 12.50      
Remaining term   4 years 3 months 7 days 3 years 11 months 15 days 4 years 11 months 15 days  
Exercisable contractual term   2 years 11 months 15 days      
Intrinsic value of warrants outstanding   $ 0