Note 5 - Intangible Assets, Net

During the six months ended September 30, 2021, the Company entered into a Patent Assignment Agreement with International Business Machines Corporation (“IBM”) to acquire an ownership interest in assigned patents. As consideration for the patents, the Company paid $231,000 (including legal fees of approximately $6,000) during the six months ended September 30, 2021.

Intangible assets, net, consists of the following (in thousands):

The following table represents the total estimated amortization of intangible assets for the five succeeding years and thereafter as of September 30, 2021 (in thousands):

For the three months ended September 30, 2021 and 2020, amortization expense was approximately $51,000 and $10,000, respectively. For the six months ended September 30, 2021 and 2020, amortization expense was approximately $98,000 and $20,000, respectively.