Quarterly report pursuant to Section 13 or 15(d)

Stock options and warrants (Schedule of Stock-based Compensation) (Details)

v3.5.0.2
Stock options and warrants (Schedule of Stock-based Compensation) (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation $ 176,388 $ 347,581 $ 224,272 $ 780,983
Selling, general and administrative expenses [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation 176,388 303,644 221,712 696,006
Research and development expenses [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation $ 43,937 $ 2,560 $ 84,977