Supplemental disclosure of cash flow information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Supplemental disclosure of cash flow information
Interest paid in cash	$ 9,669	$ 1,332
Non-cash transactions:
Dividends declared but not paid	1,289,854	1,282,086
Transfers from inventory to property, plant and equipment and construction in progress	73,464	443,018
Transfers from construction in progress to property, plant and equipment	1,653,501	7,755,375
Right-of-use assets obtained in exchange for new operating lease liabilities	299,992	2,429,305
Purchase of equipment through issuance of long-term debt	$ 122,292	$ 78,899