Digital logic gates in soft, conductive mechanical metamaterials

Abstract

Integrated circuits utilize networked logic gates to compute Boolean logic operations that are the foundation of modern computation and electronics. With the emergence of flexible electronic materials and devices, an opportunity exists to formulate digital logic from compliant, conductive materials. Here, we introduce a general method of leveraging cellular, mechanical metamaterials composed of conductive polymers to realize all digital logic gates and gate assemblies. We establish a method for applying conductive polymer networks to metamaterial constituents and correlate mechanical buckling modes with network connectivity. With this foundation, each of the conventional logic gates is realized in an equivalent mechanical metamaterial, leading to soft, conductive matter that thinks about applied mechanical stress. These findings may advance the growing fields of soft robotics and smart mechanical matter, and may be leveraged across length scales and physics.

A mechanical metamaterial with reprogrammable logical functions

“…Thus, considering the mechanism of the ReMM is independent of its scale, the whole system is scalable. Although such scales are still much larger than those commercially available in IC industry (e.g., 5nm-chip), they are sufficient to fulfill the application of ReMM in constructing mechanical systems with embedded intelligence 10 , 13 , 14 , 27 , 33 .…”

“… 41 . Accordingly, the ReMM is expected to serve as a platform for constructing reusable, multifunctional, and reprogrammable robotic material 13 , 14 with robust sensing-analyzing-response function, which can benefit the development of mechanical systems with embedded intelligence. For the curved-beam-based system, the environment information can be transformed into a mechanical signal by delicately designing the beams’ material and preparation technology 33 .…”

“…Moreover, potential applications of mechanical computation for constructing intelligent mechanical systems have renewed the interest in mechanical computation in the last decade 6 – 8 . The intelligence of mechanical systems including soft robotics 9 , 10 , microelectromechanical systems (MEMS) 11 , 12 , and robotic materials 13 , 14 , depends upon their embedded logical functions. Such systems can sense and analyze external stimuli and, based on the results, provide appropriate responses.…”

Recent Progress in Active Mechanical Metamaterials and Construction Principles

“…By adjusting the combination of materials or the curvature of the structures, various metamaterials with adjustable thermal expansion coefficients can be obtained. It has been discussed in Sections 2.1.2 [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ,…”

“…The most commonly used stimuli‐responsive materials include shape memory polymers (SMPs), liquid crystal elastomers (LCEs), hydrogels, and some other composites. If the mechanical metamaterials are reconstructed by replacing the conventional materials with stimuli‐responsive materials, they will be able to react to the stimuli of external physical fields, such as, heat, [ 18 , 19 , 20 ] chemicals, [ 21 , 22 ] light field, [ 23 , 24 ] electric current, [ 25 , 26 ] magnetic field, [ 27 , 28 , 29 ] and pressure action. [ 30 , 31 ] When stimulated, the metamaterials can automatically deform, make motions, and change their structural properties or functions according to external environments, which thus can be named active mechanical metamaterials (AMMs).…”