Information Concerning Product Lines, Geographic Information and Revenue Concentration - Schedule of Revenue by Shipment Destination (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 3,026	$ 2,717	$ 6,196	$ 5,667
Asia Pacific (1)
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	1,676	1,779	3,409	3,506
North America (2)
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	1,090	638	2,223	1,457
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	260	300	564	704
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 578	$ 875	$ 1,100	$ 2,000
Percentage of total revenue	19.00%	32.00%	18.00%	35.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 1,000	$ 604	$ 2,100	$ 1,400
Percentage of total revenue	34.00%	22.00%	35.00%	25.00%