  The fields of soft and bio-inspired robotics promise to imbue synthetic
systems with capabilities found in the natural world. However, many of these
biological capabilities are yet to be realized. For example, vines in nature
direct growth via localized responses embedded in the cells of vine body,
allowing an organism without a central brain to successfully search for
resources (e.g., light). Yet to date, vine-inspired robots have yet to show
such localized embedded responsiveness. Here we present a vine-inspired robotic
device with material-level responses embedded in its skin and capable of
growing and steering toward either a light or heat stimulus. We present basic
modeling of the concept, design details, and experimental results showing its
behavior in response to infrared (IR) and visible light. Our simple design
concept advances the capabilities of bio-inspired robots and lays the
foundation for future growing robots that are capable of seeking light or heat,
yet are extremely simple and low-cost. Potential applications include solar
tracking, and in the future, firefighting smoldering fires. We envision using
similar robots to find hot spots in hard-to-access environments, allowing us to
put out potentially long-burning fires faster.
