Flash cards have made it so easy to store volumes of data that would have formerly fitted on thousands of floppy disks. The downside though is that if the flash device is deleted or formatted then the data recovery process has more files to find. This article looks at how data recovery software is capable of finding your files and points out some of the nuances of flash memory.
The big positive thing about flash based devices is that they use the same FAT 32 file system common to many internal hard drives and other forms of external storage devices. This means they need to have a file allocation table (FAT), master boot record and a boot sector.
It also means that any data recovery tool capable of finding files on a hard drive will work on finding documents in your flash card when plugged into your computer.
Data recovery software for FAT-32 systems are very prevalent these days with many commercial and freeware options (e.g. CG Security & PC Inspector both have free tools).
They all operate in the same manner by reading the FAT to identify files (even deleted ones are indexed in the FAT) and scanning the flash memory for signs of data clusters (how each file is stored). The commercial tools will have a better chance of finding formatted data by analyzing the data clusters and reassembling the recognizable documents you work with.
One thing to keep in mind is the lifespan of flash memory. Each memory switch will fail after a certain number of read/write commands. For regular users, this could take decades to occur. But if you use the flash card for running software (including and operating system) then the memory will fail quicker, so be warned, that data recovery will not be possible once this mechanical failure occurs.