Income Taxes (Deferred Income Taxes) (Details) - USD ($)
Dec. 31, 2015
Dec. 31, 2014
Current deferred tax assets:    
Inventories $ 93,600 $ 188,300
Bad debt reserve 23,700 65,200
Accrued expenses 0 25,100
Total current deferred tax assets 117,300 278,600
Long-term deferred tax assets:    
Net operating loss carryforwards 3,221,000 2,982,100
Foreign net operating loss carryforwards 0 291,100
Federal and state tax credit carryforward 608,000 421,700
Patents and intangibles 68,100 73,000
Stock compensation 89,800 89,700
Other long term 45,500 142,100
Total long-term deferred tax assets 4,032,400 3,999,700
Total deferred tax assets 4,149,700 4,278,300
Current deferred tax liabilities:    
Prepaid expenses (64,600) (59,900)
Long-term deferred tax liabilities:    
Property, plant and equipment (612,800) (976,400)
Total deferred tax liabilities (677,400) (1,036,300)
Deferred tax valuation allowance (3,472,300) (3,242,000)
Net deferred tax assets (liabilities) $ 0 $ 0