Note 9 - Intangible Assets, Net

6 Months Ended

Jun. 30, 2021

Notes to Financial Statements

Intangible Assets Disclosure [Text Block]

Note 9.  Intangible Assets, net

Intangible assets consisted of the following for the periods indicated (in thousands):

	June 30, 2021
	Gross		Accumulated			Intangible
	Amount		amortization			assets, net
Patents	$	8,362	$	(4,480	)	$	3,882
Trademarks		22		(16	)		6
Total intangible assets	$	8,384	$	(4,496	)	$	3,888

	December 31, 2020
	Gross		Accumulated			Intangible
	Amount		amortization			assets, net
Patents	$	8,158	$	(4,165	)	$	3,993
Trademarks		21		(15	)		6
Total intangible assets	$	8,179	$	(4,180	)	$	3,999

For the three and six months ended June 30, 2021 and 2020, amortization expense for intangible assets, included in general and administrative expenses on the income statement, was each $0.1 million. The remaining weighted average amortization period for intangible assets is approximately 6 years.

At June 30, 2021, future amortization expense for intangible assets is estimated to be (in thousands):

2022	$	609
2023		609
2024		609
2025		609
2026		609
thereafter		843
	$	3,888