Consolidated Balance Sheets - USD ($)	Dec. 31, 2016	Mar. 31, 2016
Assets
Cash and cash equivalents	$ 2,100,089	$ 7,030,230
Accounts receivable	1,163,316	481,404
Costs and estimated earnings in excess of billings on uncompleted contracts	29,917	60,296
Inventories	1,749,735	2,271,271
Prepaid expenses and other current assets	259,682	272,597
Total current assets	5,302,739	10,115,798
Property and equipment, at cost:
Land	1,683,330	1,683,330
Building	4,516,301	4,516,301
Machinery and equipment	7,052,740	7,089,332
Property, plant and equipment, gross	13,252,371	13,288,963
Less accumulated depreciation	(7,590,641)	(7,241,769)
Net property and equipment	5,661,730	6,047,194
Patent costs, net of accumulated amortization of $932,564 and $916,960, respectively	213,326	249,414
Trademark costs, net of accumulated amortization of $80,885 and $77,514, respectively	94,955	98,327
Noncurrent inventories		6,840,170
Total assets	11,272,750	23,350,903
Liabilities and Stockholders' Equity
Accounts payable	809,950	364,841
Other current liabilities	1,318,941	985,435
Total current liabilities	2,128,891	1,350,276
Other long-term liabilities	141,667	288,889
Total liabilities	2,270,558	1,639,165
Commitments and contingencies (Note 7)
Stockholders' Equity [Abstract]
Common stock, $0.01 par value, 75,000,000 shares authorized; 48,519,313 and 48,330,286 shares issued and outstanding, respectively	485,193	483,303
Additional paid-in capital	128,409,933	128,103,861
Accumulated deficit	(119,892,934)	(106,875,426)
Total stockholders' equity	9,002,192	21,711,738
Total liabilities and stockholders' equity	$ 11,272,750	$ 23,350,903