“Intelligence in Materials”: Self-Powered Stimuli-Responsive Systems that Perform Advanced Autonomous Analysis and Operations

Date: 2022/05/12 - 2022/05/12

Academic Seminar: “Intelligence in Materials”: Self-Powered Stimuli-Responsive Systems that Perform Advanced Autonomous Analysis and Operations

Speaker: Dr. Siowling Soh, National University of Singapore

Time: 9:00 a.m.-10:00 a.m., May 12th, 2022

Location: via Feishu.

Abstract

Intelligent systems are characterized by their ability to sense their surroundings, analyze the surrounding signals, and provide a logical response. Intelligence is exhibited in many complex biological systems such as human beings and animals. Materials (e.g., brick, wood, or polymer), however, are generally regarded as static, passive, and far from being considered as “intelligent”.

This presentation discusses the approach of creating small-scale self-powered materials that are capable of autonomous “intelligent” analysis and operations. Stimuli-responsive polymers are used as basic building blocks for sensing and powering the materials. By designing the combination of these stimuli-responsive polymers with physical-chemical phenomena and molecular interactions, a general class of “stimuli-responsive functions” can be created. In particular, we construct analytical functions (i.e., the “thinking” unit), regulatory functions, and practical functions for responding to their surroundings. For analytical functions, we showed that the combination of a stimuli-responsive polymer and an asymmetric unsteady-state reaction diffusion allows the material to perform calculus: the analysis of the temporal derivative of concentration of the medium. Hence, we showed that basic inherent properties of materials are capable of directly performing highly advanced analytical functions (e.g., advanced mathematical functions). We further showed that assemblies of stimuli-responsive polymers can produce the functions of multiple logic gates that serve as integrated circuits. For regulatory functions, stimuli-responsive polymers are designed to perform the functions of gating and self-amplification. For practical functions, simple designs of stimuli-responsive polymers are found to produce large amounts of force onto their surroundings (e.g., for gripping and rupturing cancer cells). Charging with static charge (i.e., generated by the separation of charge at interfaces of matter) gives rise to motion of the materials by external electric fields. Therefore, complex self-powered systems can thus be created by combining stimuli-responsive polymers and stimuli-responsive functions for carrying out autonomous “intelligent” analysis and operations for a wide range of applications.

Biography

Siowling Soh received his Ph.D. degree from Bartosz Grzybowski at Northwestern University and studied under George Whitesides at Harvard University as a Post-doctoral Fellow. His current research at the National University of Singapore is highly interdisciplinary that includes materials science, physics, and chemistry. His research involves responsive, programmable, and functional polymers and separation of charge at interfaces of matter for creating intelligence in materials. These fields of research have applications in healthcare (e.g., targeted drug delivery), clean energy, and flexible electronics. He is currently the lead organizer of a new symposium (SF01) at the MRS Fall meeting, Young Investigator at ACS Applied Materials & Interfaces, Fellow of the Royal Society of Chemistry, and Editorial board member of the Journal of Controlled Release due to his works on smart drug delivery systems.