string convert to binary 8

how convert string (more than one character, two, three......) to 8 binary

Answer 1

[Walter Roberson]

bit_vector = reshape((dec2bin(uint8(TheCharacterVector), 8) - '0').', 1, []);

[LEKHCHINE Somia]

sorry may be my question was not clear

my object is to convert 'something like password or any thing ex:(hello)' to '8 bits ex:(10101010)'

so I want to insert it like watermark in my frame because I use dct algorithm