Debts - Additional information (Details)				1 Months Ended							3 Months Ended					9 Months Ended		12 Months Ended
	Oct. 04, 2021 USD ($) $ / shares shares	Jul. 16, 2021 USD ($)	Feb. 12, 2020 shares $ / shares	Dec. 31, 2021 USD ($)	Oct. 31, 2021 USD ($) shares	Sep. 30, 2021 USD ($) $ / shares	Jul. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($) $ / shares	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Mar. 31, 2021 USD ($)	May 18, 2021 USD ($)	Mar. 01, 2021 USD ($)	Dec. 31, 2019 USD ($)	Jul. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Apr. 04, 2018 USD ($)	Oct. 31, 2017 USD ($)
Line of Credit Facility [Line Items]
Aggregate principal amount of loans outstanding				$ 12,368,000							$ 12,368,000					$ 12,368,000
Interest expense accrued																77,000		$ 150,000
Outstanding balance on line of credit facility				12,400,000					$ 10,200,000		12,400,000			$ 10,200,000		12,400,000		10,200,000
Changes in fair value of promissory note											0				$ 973,000	605,000	$ (1,394,000)
Conversion price per share on convertible note payable (in dollars per share) | $ / shares			$ 5.12
Other Nonoperating Income (Expense)											(1,503,000)				(571,000)	(3,502,000)	(1,626,000)
Interest expense											187,000				191,000	611,000	571,000
Number of common stock shares converted per preferred share (in shares) | shares	3,120,000
Term of cooperation and development agreement.										3 years
Accrued and unpaid interest on promissory note						$ 600,000
Yaskawa
Line of Credit Facility [Line Items]
Conversion price per share on convertible note payable (in dollars per share) | $ / shares	$ 5.00		$ 5.12			$ 5.00						$ 5.00
Number of shares issued | shares	3,120,000
Warrant to purchase shares issued, number of shares	$ 650,000					$ 650,000						$ 650,000
Exercise price (in usd per share) | $ / shares	$ 6.00					$ 6.00						$ 6.00
Exercisable period of warrants (in years)	3 years					3 years						3 years
Accounts Payable and Accrued Liabilities
Line of Credit Facility [Line Items]
Interest expense											0				153,000	316,000	915,000
Yaskawa
Line of Credit Facility [Line Items]
Letter of intent for development activities										$ 4,000,000
Proceeds from collaborators							$ 750,000			1,000,000
Revenue recognized for collaboration development activities				375,000		$ 375,000		$ 333,000	333,000	$ 333,000	375,000	$ 375,000	$ 333,000	333,000	333,000
Loan and Security Agreement (LSA)
Line of Credit Facility [Line Items]
Long-term loan facility																								$ 15,000,000
Aggregate principal amount of loans outstanding				$ 0					10,000,000		0			10,000,000		0		10,000,000
Tranche A Loan
Line of Credit Facility [Line Items]
Long-term loan facility																								5,000,000
Tranche B Loan
Line of Credit Facility [Line Items]
Long-term loan facility								$ 8,000,000					$ 8,000,000							$ 10,000,000		$ 8,000,000	$ 8,000,000	10,000,000
Tranche B-1 Loan
Line of Credit Facility [Line Items]
Long-term loan facility																			$ 2,000,000		$ 2,000,000		$ 2,000,000
Repayment of Nexperia debt		$ 8,000,000
Tranche C Note
Line of Credit Facility [Line Items]
Long-term loan facility																								12,000,000
Revolving loan																								$ 10,000,000
Interest rate per annum																								6.00%
Interest expense accrued											$ 184,000				153,000	$ 534,000	458,000
Yaskawa Note
Line of Credit Facility [Line Items]
Interest rate per annum				1.00%							1.00%					1.00%									1.00%
Changes in fair value of promissory note															(973,000)	$ (605,000)	1,400,000
Unsecured subordinated convertible promissory note				$ 0	$ 15,600,000	$ 15,000,000			15,523,000		$ 0	$ 15,000,000		15,523,000		0		15,523,000							$ 15,000,000
Maximum number of shares of common stock issuable (in shares) | shares			3,076,171
Interest expense											3,000				$ 38,000	77,000	$ 113,000
Accrued interest on promissory note				0					$ 523,000		0			$ 523,000		0		$ 523,000
Yaskawa Note | Yaskawa
Line of Credit Facility [Line Items]
Principal and unpaid interest of convertible note	$ 15,600,000
Number of shares issued | shares					3,120,000
Other Nonoperating Income (Expense)											1,200,000					1,200,000
Principal amount of long term loan facility				15,000,000							15,000,000					15,000,000
Accrued interest on promissory note				$ 600,000							$ 600,000					$ 600,000
Number of common stock shares converted per preferred share (in shares) | shares	3,120,000