OneNote is going from strength to strength – that too across all kinds of devices. Many of us have handwritten notes. Handwriting search was limited to notes viewed on PC / Windows Tablets earlier. Now it is available on Android and iPad as well.
The only pre-requisite is that the content (the OneNote Notebook) must be stored on OneDrive. If you already have handwritten notes, those will be searchable immediately. If you have actually captured notes just now using Android or iPad, (of course you need a stylus for this), you need to wait for few minutes for the notes to be made searchable.
Try it out. It is amazing.
One Precaution: Make sure you take the notes horizontally. If these are tangential or angled, the recognition is not very effective.
Also remember that the processing of handwriting happens on the OneDrive server. Therefore, you need internet connection for this kind of search to be available.
Read this article to know more about using handwriting in OneNote.
Writing notes in OneNote: Practical Guidelines