Research and development expenses

6 Months Ended

Jun. 30, 2021

Research and development expenses

Research and development expenses

15.Research and development expenses

	Three months ended				Six months ended
	June 30, 2021		June 30, 2020		June 30, 2021		June 30, 2020
Labor	$	4,092,829	$	883,029	$	5,704,755	$	1,800,974
Materials		311,991		499,428		651,750		720,264
	$	4,404,820	$	1,382,457	$	6,356,505	$	2,521,238