Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 23,186	$ 10,218
Short-term investments		19,022
Accounts receivable, net	3,379	1,731
Inventory	907	252
Prepaid expenses and other current assets	1,596	1,264
Total current assets	29,068	32,487
Property and equipment, net	11,970	14,911
Operating lease right-of-use assets	3,110	4,590
Intangible assets, net	589	731
Goodwill	278	278
Other assets	472	602
TOTAL ASSETS	45,487	53,599
Current liabilities
Accounts payable and accrued expenses	4,818	7,095
Other current liabilities	2,311	2,338
Current portion of long-term notes payable	1,887	528
Deferred revenue	25	98
Total current liabilities	9,041	10,059
Common stock warrant liability	7,233
Operating lease liabilities	1,817	2,994
Other long-term liabilities	872	1,630
Long-term notes payable	1,964
Total liabilities	20,927	14,683
Commitments and Contingencies (Note 14)
STOCKHOLDERS’ EQUITY
Preferred stock - 25,000,000 shares authorized, 0 shares issued and outstanding at September 30, 2020 and December 31, 2019
Common stock – $.001 par value; 250,000,000 shares authorized; 38,912,005 and 27,374,653 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	39	27
Additional paid-in capital	492,676	474,174
Accumulated other comprehensive income		72
Accumulated deficit	(468,155)	(435,357)
Total stockholders’ equity	24,560	38,916
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 45,487	$ 53,599