dna origami robots were designed using cadnano 2.0 ( http://cadnano.org ) , and folded using m13mp18 ssdna as scaffold strand in tae buffer containing 10 mm magnesium .
robots were imaged using tem and afm , and their states were measured using flow cytometry .
adult blaberus discoidalis were maintained at constant room temperature in humid plastic cages with dry pet food and fresh fruit ad libitum .
robots ( typically 0.1 - 3 pmol in 10 ul buffer ) were injected into the animal hemocoel between the two last abdominal sternites .
hemolymph was extracted through the arthrodial membrane and mixed with anticoagulant buffer before hemocytes analysis . for detailed methods
 biological systems are collections of discrete molecular objects that move around and collide with each other . 
 cells carry out elaborate processes by precisely controlling these collisions , but developing artificial machines that can interface with and control such interactions remains a significant challenge . 
 dna is a natural substrate for computing and has been used to implement a diverse set of mathematical problems1 - 3 , logic circuits4 - 6 and robotics7 - 9 . 
 the molecule also naturally interfaces with living systems , and different forms of dna - based biocomputing have previously been demonstrated10 - 13 . here we show that dna origami14 - 16 can be used to fabricate nanoscale robots that are capable of dynamically interacting with each other17 - 18 in a living animal . 
 the interactions generate logical outputs , which are relayed to switch molecular payloads on or off . as a proof - of - principle 
 , we use the system to create architectures that emulate various logic gates ( and , or , xor , nand , not , cnot , and a half adder ) . following an ex vivo prototyping phase 
 , we successfully employed the dna origami robots in living cockroaches ( blaberus discoidalis ) to control a molecule that targets the cells of the animal . 
Methods summary
Supplementary Material