Development of a facile one-pot synthesis method for an ingestible pH sensitive actuator

Abstract

Edible devices are an emergent technology and in this paper the simplicity and efficacy that poly(acrylic acid)/calcium hydroxide possess in creating a pH sensitive ingestible actuator which responds to acidic environments such as gastric fluid is demonstrated. It was found that poly(acrylic acid)/calcium hydroxide hydrogels exhibit reversible actuation upon submerging in 0.1 M sodium citrate for 2 hours. Our results show that these hydrogels can restore their compressive stress to 0.19 ± 0.06 MPa, swelling ratio to 26 ± 2 and volume to 56% ± 3% of its original volume. This work offers new possibilities for developments in a variety of fields such as drug delivery, 4D printed materials, soft robotics and edible devices.

Bioresorbable Bilayered Elastomer/Hydrogel Constructs with Gradual Interfaces for the Fast Actuation of Self-Rolling Tubes

“…In the frame of biomedical applications, biomaterials that can undergo a morphological or mechanical transition in response to a stimulus are highly sought after. Shape memory materials and reversibly swelling hydrogels or actuators − are examples of such biomaterials that find applications in the frame of medical devices, diagnostics, or drug delivery. In this context, self-rolling tubes provide interesting opportunities to design spatially constrained medical devices suitable for the encapsulation of drugs or cells.…”

“…The samples were elongated to 15% and subsequently let to recover (0%) before immediately being stretched again to 15% (nine cycles). To evaluate the ability of the material to deform reversibly without loss of energy, the resilience was calculated according to eq (5). It was calculated from the value of the ninth cycle.…”

Biodegradable Humidity Actuators for Sustainable Soft Robotics using Deliquescent Hydrogels

“…This has driven scientists to seek green and sustainable solutions for soft robotic development. Intelligent materials [2] are materials imbued with unique chemistry which enable controlled deformation in response to a range of external stimuli such as light [3], temperature [4], pH [5], [6], magnetic fields [7] and electrical fields [8], [9]. By constructing robots from these smart materials, the ability to autonomously respond to the environment reduces the need not only for complex control electronics, but also internal energy sources.…”