Shaping a Soft Future
Abstract
Existing devices—such as cell phones, computers, and robots – are made from rigid materials, which is in direct contrast to the soft materials that compose the human body. In this talk, I will discuss several topics related to studying and harnessing soft materials within the context of creating devices (actuators, sensors, electronics) with tissue-like properties.
• Liquid metal: Gallium-based liquid metals are often overlooked despite their remarkable properties: melting points below room temperature, water-like viscosity, low-toxicity, and effectively zero vapor pressure (they do not evaporate). Normally small volumes of liquids with large tension form spherical or hemi-spherical structures to minimize surface energy. Yet, these liquid metals can be patterned into non-spherical shapes (cones, wires, antennas) due to a thin, oxide skin that forms rapidly on its surface. For example, they can be injected into hollow elastomeric tubes to create stretchable wires for wearables. By injecting them into hydrogel fibers, it is possible to create electrical double layers between the metal and gel that is useful for energy harvesting and sensing. Recently, we have discovered a simple way to separate the oxide from the metal as a way to deposit 2D-like oxides at ambient conditions.
• Shape reconfiguration: Perhaps the most fascinating aspect of liquid metals is the ability to use interfacial electrochemistry to remove/deposit the oxide to manipulate the surface tension of the metal over unprecedented ranges (from the largest tension of any known liquid to near zero!). This allows manipulating the shape and position of the metal for shape reconfigurable devices.
This work has implications for soft and stretchable electronics; that is, devices with desirable mechanical properties for human-machine interfacing, soft robotics, and wearable electronics.
Biography
Syed Ahmed Jaseem received his B.E. in Chemical Engineering from B.M.S. College of Engineering, India (2018), and his M.S. in Chemical Engineering from North Carolina State University (2023). He is currently pursuing a Ph.D. in Chemical Engineering at North Carolina State University under Professor Michael Dickey. Jaseem’s research focuses on developing soft, stretchable devices for sustainable energy harvesting, with an emphasis on hydrogels, liquid metals, and sintering of liquid metal particles.