BALANCE SHEET COMPONENTS (Tables)

12 Months Ended

Dec. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of accounts receivable, net and activity in allowance for uncollectible accounts

Accounts receivable, net consist of the following (in thousands):

	As of December 31,
	2022		2021
Accounts receivable	$	119	$	77
Allowance for uncollectible accounts	(6)		—
Accounts receivable, net	$	113	$	77

The following is the activity in the allowance for uncollectible accounts (in thousands):

	Years Ended December 31,
	2022		2021
Balance as of beginning of year	$	—	$	—
Increase in provision	8		—
Amounts written off, less recoveries	(2)		—
Balance as of end of year	$	6	$	—

Schedule of inventory, net and activity in reserve for obsolescence

Inventory, net consist of the following (in thousands):

	As of December 31,
	2022		2021
Raw materials	$	772	$	937
Work in progress	0		5
Finished goods	99		88
Total inventory	871		1,030
Reserve for obsolescence	(18)		(29)
Inventory, net	$	853	$	1,001

The following is the activity in the reserve for obsolescence (in thousands):

	Years Ended December 31,
	2022		2021
Balance as of beginning of year	$	29	$	123
Increase in reserve	—		13
Amounts relieved	(11)		(107)
Balance as of end of year	$	18	$	29

Schedule of prepaid expenses

Prepaid expenses consist of the following (in thousands):

	As of December 31,
	2022		2021
Software licenses	$	157	$	14
Marketing programs and conferences	74		66
Insurance	61		109
Patents	39		41
Professional services	41		—
Other	6		—
Total prepaid expenses	$	378	$	230

Schedule of property and equipment, net

Depreciation on property and equipment is computed using the straight-line method over the estimated useful lives of the respective assets as follows:

Research and development equipment	5 years
Office and computer equipment	3 years
Autos	5 years
Furniture and fixtures	7 years

Property and equipment, net consist of the following (in thousands):

	As of December 31,
	2022		2021
Research and development equipment	$	1,558	$	1,425
Office and computer equipment	800		762
Autos	54		54
Furniture and fixtures	41		41
Leasehold improvements	119		112
Total in service	2,572		2,394
Accumulated depreciation and amortization	(2,283)		(2,105)
Total in service, net	289		289
Construction in progress	5		45
Property and equipment, net	$	294	$	334

Schedule of accrued expenses

Accrued expenses consist of the following (in thousands):

	As of December 31,
	2022		2021
Compensation, severance and related benefits	$	497	$	524
Legal services	36		17
Product warranty	18		18
Personal property and franchise tax	6		5
Other	3		14
Total accrued expenses	$	560	$	578