Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details Textual)

v3.19.2
Income Taxes (Details Textual) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Dec. 31, 2017
Income Taxes (Textual)      
Change in deferred tax assets valuation allowance $ 1,538,000    
Federal [Member]      
Income Taxes (Textual)      
Net operating loss 15,045,000 $ 12,515,000 $ 6,686,000
Expiring date, description     Expiring in 2037.
State [Member]      
Income Taxes (Textual)      
Net operating loss $ 23,886,000 $ 21,049,000  
Expiring date, description expiring in 2039. expiring in 2039.  
Japan [Member]      
Income Taxes (Textual)      
Net operating loss $ 333,000 $ 319,000  
Expiring date, description expiring in 2029. expiring in 2029.  
Taiwan [Member]      
Income Taxes (Textual)      
Net operating loss $ 1,687,000 $ 879,000  
Expiring date, description expiring in 2029. expiring in 2029.  
Federal Research and Development Tax Credit [Member]      
Income Taxes (Textual)      
Research and development tax credit $ 37,000 $ 37,000  
Expiring date, description The credit begins to expire in 2034 if not utilized.    
California State Research and Development Tax Credit [Member]      
Income Taxes (Textual)      
Research and development tax credit $ 39,000 $ 39,000