Shape Memory Polymers for Body Motion Energy Harvesting and Self‐Powered Mechanosensing

Abstract

Growing demand in portable electronics raises a requirement to electronic devices being stretchable, deformable, and durable, for which functional polymers are ideal choices of materials. Here, the first transformable smart energy harvester and self-powered mechanosensation sensor using shape memory polymers is demonstrated. The device is based on the mechanism of a flexible triboelectric nanogenerator using the thermally triggered shape transformation of organic materials for effectively harvesting mechanical energy. This work paves a new direction for functional polymers, especially in the field of mechanosensation for potential applications in areas such as soft robotics, biomedical devices, and wearable electronics.

Nanostructured polymer-based piezoelectric and triboelectric materials and devices for energy harvesting applications

“…Additionally, the ability to precise control crystalline phases in polymeric materials is likely to prove beneficial in developing next-generation NGs in the coming years. Recently there have been reports on NGs made from shape memory polymers, which provide recovery from large deformation [100] or even self-healing characteristics to cutting damage on NGs [101]. Although there are a few selfhealing NGs reported based on nanostructured materials [102], most of the attempts remain focused on certain bulk polymers, and there may scope to extend such concepts to polymer-based nanocomposites in order to further increase the energy harvesting performance.…”

“…Fieldemission SEM (FE-SEM) was used to observe freed ZnO NWs ( figure 17(b)) by dissolving the PC template with chlorobenzene followed by heat treatment to burn away the PC template in a furnace at 500 °C for 30 min. XRD analysis of ZnO NWs within the PC template ( figure 17(c)) showed that the preferred orientation of the NWs is [100]. The presence of other peaks in figure 17(c) could be explained by the polycrystalline nature of the electrodeposited ZnO NWs, albeit with an overall preferred orientation.…”

“…Figure 16(c) provides the XRD patterns of bare PC template, seeded PC template, and NWs grown in the template with and without refreshed precursor, showing that the template-grown ZnO NWs were polycrystalline. The observed dominant peak of (1 0 0) indicates that ZnO NWs exhibited an oriented a-axis growth along the [100] direction, resulting from stacks of individual grown singlecrystalline nanoparticles with the preferential c-axis orientation vertical to the pore walls in the nanoconfined growth process. The polycrystalline ZnO NWs were formed due to fusing of the nanoparticles or nanorods together.…”

“…Alternatively, the NWs could have been formed of single crystallites with different orientations, but with the majority pointing along the same preferred orientation. Further HRTEM examination on a single freed ZnO nanowire ( figure 17(d)) proved the growth direction of the NWs was along the [100] axis, which was parallel to the long axis of the nanowire, possibly due to a result of stacks of single crystallite nanoparticles piled on top of one another with their [0 0 2] axis parallel to the plane of the template.…”

“…A second ZnO-PC nanocomposite synthesis method involved using a template-assisted electrodeposition (TAED) method [63] as reported by Boughey et al As before, growth of NWs with preferred [100] axis orientation parallel to the axis of the ZnO NWs was achieved. However, unlike in the case of hydrothermal synthesis, the nanowire growth here was driven by an electric potential in the presence of aqueous electrolyte solution.…”