5. Intangible Assets, net

Intangible assets as of June 30, 2018 and December 31, 2017 comprised the following (in thousands):



	June 30, 2018							December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Licensed intellectual property	$	4,750	$	(2,423	)	$	2,327	$	4,750	$	(2,126	)	$	2,624

In July 2012, the Company entered into a development collaboration and license agreement with Advanced Liquid Logic, Inc., or ALL, which was acquired by Illumina, Inc. in July 2013. Under the terms of the agreement, the Company established a collaborative program to develop in-vitro diagnostic products incorporating ALL’s proprietary electro-wetting technology in conjunction with the Company’s electrochemical detection technology. During the six months ended June 30, 2017, the Company satisfied certain commercial milestones under this agreement requiring a payment of $500,000 recorded as an addition to licensed intellectual property.

Intellectual property licenses have a weighted average remaining amortization period of 3.93 years as of June 30, 2018. Amortization expense for these licenses was $148,000 and $123,000 for the three months ended June 30, 2018 and 2017, respectively, and was $297,000 and $247,000 for the six months ended June 30, 2018 and 2017, respectively. Estimated future amortization expense for these licenses is as follows (in thousands):



Fiscal Years Ending	Future Amortization Expense
Remaining in 2018	$	296
2019	593
2020	593
2021	593
2022	252
Total	$	2,327