Caesium-137 irradiates electronic paper. An incoming gamma-ray from the Cs-137 interacts with a particle inside a micro-container by generating a recoil electron and/or a hole. Because the recoil electron physically leaves the particle, the particle is charged depending on the dose from the radiation source. And, the charge of the particles change, which results in a movement of the particles within the micro-container. After refreshing the electronic paper, a visible difference in the gray-scale can be seen. Thus, the visible difference in the gray-scale is an effect caused by the irradiation of the electronic paper, showing sensitivity to high energy radiation—thus, non-optimized electronic paper is sensitive to high energy radiation and can be used as a radiation dosimeter. In addition, electronic paper can be used for sensing chemical and bio-chemical agents, as well as detecting high energy radiation.