Untethered Soft Microrobots with Adaptive Logic Gates

Abstract

Integrating adaptative logic computation directly into soft microrobots is imperative for the next generation of intelligent soft microrobots as well as for the smart materials to move beyond stimulus-response relationships and toward the intelligent behaviors seen in biological systems. Acquiring adaptivity is coveted for soft microrobots that can adapt to implement different works and respond to different environments either passively or actively through human intervention like biological systems. Here, a novel and simple strategy for constructing untethered soft microrobots based on stimuli-responsive hydrogels that can switch logic gates according to the surrounding stimuli of environment is introduced. Different basic logic gates and combinational logic gates are integrated into a microrobot via a straightforward method. Importantly, two kinds of soft microrobots with adaptive logic gates are designed and fabricated, which can smartly switch logic operation between AND gate and OR gate under different surrounding environmental stimuli. Furthermore, a same magnetic microrobot with adaptive logic gate is used to capture and release the specified objects through the change of the surrounding environmental stimuli based on AND or OR logic gate. This work contributes an innovative strategy to integrate computation into small-scale untethered soft robots with adaptive logic gates.

Keywords: adaptive logic gates; conjugated logic gates; soft microrobots; stimuli-responsive hydrogels.

Figure 1

The construction of the microrobots with YES, AND, and OR logic gates employing PNIPAm and PAAc hydrogels. a) Schemes illustrating the microrobots with two YES gates. Inputs 0 and 1 were defined as the state of the hydrogel shrunk and swollen. Outputs 0 and 1 were defined as the state when the hole in the middle of hydrogel opened and closed; Schematic illustrations and images of the microrobots in the different states and the truth tables with b) AND gate and c) OR gate.

Figure 2

Schematic illustrations and images of the microrobots in the different states with connected logic gates and the truth tables. a) An AND gate connected with an OR gate. b) An OR gate connected with another OR gate.

Figure 3

The construction of soft microrobots with adaptive logic gate. a) The schematic diagram to switch logic operations between OR gate and AND gate and truth tables. b) Schematic illustrations and images of the soft microrobots switching AND gate to OR gate.

Figure 4

The construction of soft microrobots with adaptive logic gate employing the pH and salt dual‐responsive hydrogel. a) The schematic diagram to switch logic operation between AND and OR gate and truth tables. b) Schematic illustrations and images of the soft microrobots switching AND gate to OR gate.

Figure 5

a) Schematic illustrations and images of the process that a Teflon rod was transferred by the magnetic soft microrobot with adaptive logic gates based on an AND gate. b) The area of the AND gate and truth tables.

Figure 6

a) Schematic illustrations and images of the process that a Teflon rod was transferred by the magnetic soft microrobot with adaptive logic gates based on an OR gate. b) The area of the OR gate and truth tables.