Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Finance lease right-of-use asset	$ 13		$ 13		$ 13
Property and equipment at cost	3,042		3,042		3,477
Less: accumulated depreciation	(2,609)		(2,609)		(2,802)
Property and equipment, net	433		433		675
Depreciation	42	$ 43	129	$ 143
Loss on write-off of property and equipment	76	$ 0	76	$ 0
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,096		$ 1,096		1,308
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)			3 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)			15 years
Tooling
Property, Plant and Equipment [Line Items]
Property and equipment, gross	413		$ 413		384
Tooling | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)			2 years
Tooling | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)			5 years
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	81		$ 81		83
Useful life (in years)			5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	86		$ 86		86
Useful life (in years)			5 years
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,144		$ 1,144		1,194
Useful life (in years)			3 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	141		$ 141		169
Ultraviolet-C light disinfection robots
Property, Plant and Equipment [Line Items]
Property and equipment, gross	0		$ 0		105
Useful life (in years)			5 years
Loss on write-off of property and equipment	76
Projects in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 68		$ 68		$ 135