Soft robotics is a growing research field promising to apply automation to new areas of our societies such as medicine, agriculture and exploration. However, since soft robotics is a relatively recent research field, many fundamental components of soft robots still demonstrate disappointing capabilities. Indeed, actuation is one of the most vital requirement of robots but it is yet to be solved adequately. This proposal describes the development and characterization of a new soft actuator. We call these innovative soft actuator “M-SCPAs”, as they are inspired by recent advances in Magnetoactive polymeric fiber (MAEs) and Supercoiled Polymer Actuators (SCPAs). M-SCPAs will be manufacThis proposal aims at creating a new type of soft actuator. Soft actuators are a key component of the soft robotics research field, with applications in medical, agricultural or wearable technologies. We propose to use “M-SCPAs”, named after the 2 key distinct concepts used in their design. -The first key concept is the use of a magnetoactive (M-) polymeric fiber. Inspired by recent advances in magnetoactive materials, we propose to embed strongly magnetized ferromagnetic particles within an extruded polymer fiber. When exposed to a magnetic field, the particles will internally pivot, and the fiber contract. -The second key concept is the use of an helical structure similar to the one used by “Supercoiled Polymer Actuators” (SCPAs). The twisting of a polymeric fiber creates a three-dimensional structure akin to a typical steel spring. From this structure is derived inherent softness, convenient form factor, as well as increased contractile capabilities. The proposal details the combination of these two ideas to create a new type of actuator overcoming each of the respective original actuators limitations. The proposal also proposes the demonstration of these actuators through the manufacture of a soft wearable haptic device powered and its subsequent use in an haptic feedback study.
Halide perovskites exhibit many ideal properties for photovoltaics, as highlighted by the fact that lead halide solar cells (SCs) have now reached efficiencies >25%, a value close the theoretical limit of single-junction SCs. A strategy to overcome this limitation is to combine two SCs, e.g. two perovskites of different compositions, into a tandem device to reduce thermalization and incomplete absorption losses. To maximize power output, each sub-cell must generate a maximum photocurrent matching that of the other sub-cell. This can be achieved by a. careful optimization of the perovskites thicknesses, b. minimizing parasitic absorption in transport layers and electrodes, and c. depositing the SCs on textured substrates. Textures are employed by some SC technologies, e.g. silicon, to enhance absorption and reduce reflection losses. Still, the use of textures in perovskite-based devices has been extremely challenging. Record perovskite-based single-junction and tandem devices rely on solution-processing (spin-coating), complicating and often preventing the uniform coverage of textured surfaces, in addition to hindering their deployment on industry-relevant sizes. This proposal aims to tackle both challenges by producing 30% perovskite-perovskite tandems, where all the functional layers (incl. perovskites) are grown conformally on textured substrates with high uniformity. To track and improve the optoelectronic quality of the perovskites when developing new processing routes, a combination of three in-situ optical spectroscopies (Absorption, PL & Raman) will be implemented. The methods will offer direct insights into the (trans-)formation of perovskites and emergence of defects or unwanted phases. With the means to monitor the quality of the perovskites, the optoelectronic quality of narrow- and wide-bandgap perovskites will be improved through process and additive engineering to finally yield highly efficient textured perovskite-perovskite tandems.