A Passive Elastic-Folding Mechanism for Stackable Airdrop Sensors. - Damyon Kim; Yuichi Honjo; Tatsuya Iizuka; Naomi Okubo; Naoto Endo; Hiroshi Matsubara; Yoshihiro Kawahara; Naoto Morita; Takuya Sasatani (CoRR, 2026)