BALANCE SHEET COMPONENTS (Tables)

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

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

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

	September 30, 2025		December 31, 2024
Accounts receivable	$	464	$	339
Allowance for uncollectible accounts	(10)		(4)
Accounts receivable, net	$	454	$	335

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Balance as of beginning of period	$	10	$	4	$	4	$	4
Increase in provision	—		(2)		6		2
Amounts written off, less recoveries	—		2		—		(2)
Balance as of end of period	$	10	$	4	$	10	$	4

Schedule of inventory, net and activity in reserve for obsolescence

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

	September 30, 2025		December 31, 2024
Raw materials	$	643	$	719
Work in progress	5		1
Finished goods	119		74
Total inventory	767		794
Less: reserve for obsolescence	—		—
Inventory, net	$	767	$	794

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Balance as of beginning of period	$	—	$	—	$	—	$	5
Increase in reserve	—		—		—		—
Amounts relieved	—		—		—		(5)
Balance as of end of period	$	—	$	—	$	—	$	—

Schedule of prepaid expenses

Prepaid expenses and other current assets consisted of the following (in thousands):

	September 30, 2025		December 31, 2024
Software licenses	$	78	$	112
Professional services	58		18
Inventory	58		—
Insurance	47		27
Equity offering costs	34		146
Rent	12		38
Marketing programs and conferences	8		21
Other	18		15
Total prepaid expenses and other current assets	$	313	$	377

Schedule of property and equipment, net

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

	September 30, 2025		December 31, 2024
Research and development equipment	$	1,908	$	1,826
Office and computer equipment	494		494
Autos	54		54
Furniture and fixtures	46		46
Leasehold improvements	272		157
Total in service	2,774		2,577
Accumulated depreciation and amortization	(2,345)		(2,242)
Total in service, net	429		335
Construction in progress	—		72
Property and equipment, net	$	429	$	407

Schedule of accrued expenses

Accrued expenses consisted of the following (in thousands):

	September 30, 2025		December 31, 2024
Compensation and related benefits	$	238	$	244
Legal and consulting professional services	81		30
Product warranty and other	14		4
Total accrued expenses	$	333	$	278

Schedule of maturities of notes payable

As of September 30, 2025, future principal payments were as follows (in thousands):

2025	$	14
2026	61
2027	68
2028	65
2029	12
Thereafter	—
Total principal payments	220
Less: current portion of notes payable	(60)
Notes payable, less current portion	$	160