Energy Harvesting Using a Torsional Mode L-Shaped Unimorph Structure: Modeling and Experimental Investigations

Previous studies have proved that the piezoelectric L-shaped beam-mass structure is a good candidate to harvest energy from ambient mechanical vibration. However, most researches merely focused on bending mode of the structure, which only can capture energy from in-plane base excitation. To fully exert the advantages of L-shaped harvesters, this paper will explore their energy harvesting performance on torsional mode with out-of-plane base excitation. The electromechanical coupling governing equation of the L-shaped harvester in torsional mode is derived by applying Gauss's law and the Euler–Bernoulli beam theory with linear assumption, and the analytical results are also validated with experimental results. In addition, the influences of key geometric parameters on the resonance frequency and output voltage of the harvester are also presented. This work demonstrates the feasibility of utilizing torsional mode of the L-shaped unimorph structure to harvest energy from out-of-plane mechanical vibration, which shows the potential of designing multi-directional and multi-frequency L-shaped harvesters.

KINK SOLITONS IN DNA

We study DNA dynamics relying on the plane-base rotator model for DNA. It is shown that this dynamics can be represented by kink and antikink solitons. We demonstrate that two velocities are relevant and these are the velocities of both a double and a single stranded DNA. A key question is which one is bigger as this is related to a value of the ratio of two parameters describing the hydrogen and the covalent interactions in DNA. If the velocity of double stranded DNA is larger than one of the single stranded chain then the two ferromagnetic strands are coupled antiferromagnetically. Otherwise, the two DNA strands are coupled ferromagnetically. We discuss possible experiments based on micromanipulation techniques that should be carried out to determine these velocities and the solitonic width.

An introduction to hyperseeing and hypersculptures

PurposeThe purpose of this paper is to introduce the cybernetics audience to the fundamental interdisciplinary concept of hyperseeing and its application to hypersculptures.Design/methodology/approachBriefly, hyperseeing is seeing from multiple viewpoints in a very general sense. In particular, the author first discusses hyperseeing a sculpture. A sculpture is defined as an object in a fixed position relative to a horizontal plane (base, ground). Two sculptures are congruent if they consist of the same object. A hypersculpture is a set of congruent sculptures. A hypersculpture is a more complete presentation of the sculptural possibilities of an object.FindingsA specific example is given of hyperseeing a knot sculpture made of copper tubing.Originality/valueThe paper demonstrates how the study of hypersculptures facilitates gaining a deeper understanding and appreciation of sculpture.