Revenue - Schedule of total revenue disaggregated by geographic region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue by country of domicile:
Revenue	$ 7,426	$ 4,502
% of Revenue	100.00%	100.00%
Japan
Revenue by country of domicile:
Revenue	$ 3,948	$ 3,404
% of Revenue	53.00%	75.00%
United States
Revenue by country of domicile:
Revenue	$ 2,400	$ 699
% of Revenue	32.00%	16.00%
China
Revenue by country of domicile:
Revenue	$ 880	$ 15
% of Revenue	12.00%	0.00%
Other
Revenue by country of domicile:
Revenue	$ 198	$ 384
% of Revenue	3.00%	9.00%