Unidirectional dynamic stiffness modulation enables easily insertable and conformally attachable spinal bioelectronic device. - Hong, Sunguk; Pak, Sungah; Cho, Mingeun; Ko, Matthew; Lee, Seongjae; Kim, Hyebin; Choo, Minhye; Kang, Wonok; Mun, Hyeok Jae; Park, Jiyoon; Ahn, Yong Joo; Park, Sung-Min (NPJ Flexible Electronics, 2026)