The trend to a world with ubiquitous electronics has the need for novel concepts for sensors and actuators that are lightweight, flexible, low‐cost, and also sustainable. Piezoelectric transducers on the basis of functional polymers can meet these expectations. In this work, a novel concept for paper‐embedded large‐area piezoelectric devices realized solely by means of roll‐to‐roll (R2R) mass printing and post printing technologies including inline poling are introduced. The device set‐up, as well as the process technology, offers the great opportunity for a cost‐efficient and environmentally friendly mass production of thin and flexible organic large‐area piezoelectric devices. As the functional layers are embedded into paper by the hot lamination of two poly(vinylidene fluoride‐co‐trifluoroethylene) P(VDF‐TrFE) layers, the printed electronics is protected and invisible. The paper gives insights to the R2R printing of a 500 m long web including R2R post printing processes and electrical and acoustic inline characterization. Fully R2R processed devices show a high remnant polarization of up to 78 mC m−2 and can be realized with high yield of >90%. Finally, a 360° surround‐sound installation realized with a 387 cm long paper web consisting of 56 piezoelectric speakers including wiring is presented.
Piezoelectric polymer loudspeakers have advantages like lightweight, flexibility, simple structure, and small volume, which make them favorable for a variety of applications. Herein, such loudspeakers are fabricated by screen printing the bottom and top electrodes (poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate), PEDOT:PSS) as well as the piezoelectric polymer layer (poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE)), in between on paper substrates. The dielectric properties of the printed loudspeakers are studied with dielectric spectroscopy. Thanks to the self-healing process during poling, the samples are successfully poled to saturation in spite of their large area of up to 300 cm 2 . The dependence of the acoustic output on remanent polarization and the active area of the piezoelectric layer is investigated. A sound pressure level (SPL) of about 91 dB at a distance of 1 m is obtained with array samples of five rectangular units (10 Â 6 cm 2 in area each). In particular, samples with two loudspeaker arrays printed, respectively, on both surfaces of the paper substrates are prepared, and a further increase of 6 dB in SPL is achieved when the two loudspeakers are driven in phase. The results not only deepen the understanding of fully printed piezoelectric polymer loudspeakers but also realize an SPL much higher than that reported in previous studies.
Active noise control (ANC) is a methodology that aims to attenuate acoustic noise creating a silent zone around the target. ANC techniques are particularly useful in the presence of low frequency noise, where passive control is ineffective and impractical. However, the computational cost of ANC applications involving a high number of sensors and actuators, such as active shielding, appears to be an important limitation. One possible approach to deal with this problem is to resort to decentralized control. This is a technique that decomposes a complex control problem into smaller ones that are addressed independently using different controllers. This article studies a decentralized scheme for ANC from a game-theoretical perspective. This formalizes the Nash equilibrium (i.e., the simultaneous best strategy) in the interaction between the controllers. Indeed, in the Nash Equilibrium, the control signals achieve stable conditions. In this framework, it is straightforward to analytically compare the decentralized control scheme to the standard centralized one.
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