Note 6 — Intangible Assets

Intangible assets, net consisted of the following:

At December 31, 2019 and 2018, the Company had capitalized approximately $335,224 and $354,427, respectively, for costs related to patents that have not been awarded. During the years ended December 31, 2019 and 2018, the Company wrote-off $14,707 and $56,504, respectively, in previously capitalized patent costs.

Amortization expense amounted to $79,536 and $64,981 for the years ended December 31, 2019 and 2018, respectively. Amortization expense for the succeeding five years and thereafter is $87,813 (2020‑2024) and $860,088 (thereafter).