The 2015 Luckhurst-Samulski Prize

The Luckhurst-Samulski Prize was first announced seven years ago [1] and its terms are simply that it should be awarded annually to the best paper published in Liquid Crystals in that year. The first six recipients of the Prize are listed in Table 1. In 2015, Liquid Crystals published almost 200 papers and the demanding task of selecting the best of these fell to the Prize’s Selection Committee, consisting of the Editorial Board and myself as Editor. The selection process begins with the referees who can flag a paper as being a worthy Prizewinner. These suggestions are then brought to the attention of the Selection Committee which is tasked initially with drawing up a long list of nominations for the Prize. Each Selection Committee member can nominate as many papers as they wish to feature on the long list. Those papers, which garner the most nominations, form a shortlist which is voted upon by the Selection Committee, and the paper which receives the most votes is the winner. Any member of the Selection Committee who has a paper on the shortlist is exempted from the final stage of the selection process.

Table 1. Previous winners of the Luckhurst-Samulski Prize.

Year	Authors	Title	Reference
2009	Goodby JW, Saez IM, Cowling SJ, Gasowska JS, MacDonald RA, Sia S, Watson P, Toyne KJ, Hird M, Lewis RA, Lee S-E, Vaschenko V.	Molecular complexity and the control of self-organising processes.	[2]
2010	Jakli A.	Electro-mechanical effects in liquid crystals.	[3]
2011	Skarabot M, Lokar Z, Gabrijelcic K, Wilkes D, Musevic I.	Atomic force microscope based method of measuring short cholesteric pitch in liquid crystals.	[4]
2012	Picken SJ, Dingemans TJ, Madsen LA, Francescangeli O, Samulski ET.	Uniaxial to biaxial nematic phase transition in a bent-core thermotropic liquid crystal by polarising microscopy.	[5]
2013	Pieranski P, Yang B, Burtz LJ, Camu A, Simonetti F.	Generation of umbilics by magnets and flows.	[6]
2014	Takezoe H, Araoka, F.	Polar columnar liquid crystals	[7]

For the 2015 Luckhurst-Samulski Prize the shortlist consisted of eight papers, and each would have made an outstanding winner of the Prize. I am delighted to report that the Prize has been awarded to Ali Alshomrany and Noel Clark for their paper entitled Fisheye lens conoscopy [8]. Ed Samulski announced this decision and presented the Prize to Professor Clark at a ceremony held at the 26^th International Liquid Crystal Conference at Kent State University (Figure 1). Conoscopy is an important tool in the characterisation of soft materials, and this paper describes a new approach to conoscopy which is particularly suited to the study of liquid crystals. This has involved the development of an ingenious, and inexpensive conoscopic set-up comprising a smartphone equipped with the Olloclip accessory. Remarkably, this set-up may be used for detailed conoscopic studies of liquid crystals despite its low cost. The Selection Committee considered that this elegant paper will significantly impact both research and teaching.

Figure 1. Ed Samulski (right) presenting Noel Clark (left) with the 2015 Luckhurst-Samulski Prize. (Photograph taken by Rebecca Walker.)

The remaining seven papers on the short-list were each highly commended by the Selection Committee. Five of these shortlisted papers appeared in the truly excellent Commemorative Issue of the Journal dedicated to Professor George Gray. In strict chronological order of publication, the first of these seven highly commended papers was by Marin and colleagues entitled Polymer-dispersed liquid crystal composites for bio-applications: thermotropic, surface and optical properties [9]. This paper describes the preparation of polymer-dispersed liquid crystal films (PDLCs) based on a polysulfone matrix. The comprehensive study of these PDLCs involved a wide range of techniques including POM, SEM, DSC, UV spectroscopy, photoluminescence and static contact angle measurements. The Selection Committee considered this investigation to be an important step in the development of PDLC composites for bio-applications.

In the second of the shortlisted papers entitled What makes a liquid crystal? The effect of free volume on soft matter, Goodby and co-workers provide a fascinating insight into the formation of liquid crystal and soft crystal phases in terms of free volume [10]. This involves the minimization of the free volume of the system either by molecular design, or by deformation of the molecular archictecture. The arguments are made in a highly elegant manner, and accompanied by beautiful illustrations. The scope of the paper is fantastic, ranging from conventional low molar mass materials to large and complex systems. The Selection Committee considered that this paper is destined to become a classic in the field.

The third paper was also from Goodby’s group and entitled The relationship between molecular structure and the incidence of the N_TB phase [11]. This paper focuses on odd-membered methylene-linked dimers. The authors find that there is a negative correlation between the strength of the individual dipole moments of the mesogenic units and the twist-bend nematic-nematic transition temperature. In addition, increasing the length-to-breadth ratio of the individual mesogenic units increases the twist-bend nematic-nematic transition temperature. The Selection Committee viewed this paper as an important contribution to our knowledge of structure-property relationships in twist-bend nematogens and which will stimulate further work in this area.

The fourth paper by Jokisaari and colleagues entitled Twist-bend nematic phase of the liquid crystal dimer CB7CB: orientational order and conical angle determined by ¹²⁹Xe and ²H NMR spectroscopy [12] also involved a study of the twist-bend nematic phase. Critically this paper includes the measurement of the temperature dependence of the conical angle of the director, one of the defining order parameters of the fascinating N_TB phase. The ¹²⁹Xe and ²H NMR experiments show good agreement, and analysis of the two quadrupolar splittings allowed the determination, for the first time, of the off-diagonal element of the Saupe ordering matrix which reflects the phase chirality. The Selection Committee viewed this as a key investigation in our developing understanding of the N_TB phase and which will certainly trigger further experimental and theoretical works.

The fifth paper by Gleeson and co-workers entitled Liquid crystal blue phases: stability, field effects and alignment [13] was considered by the Selection Committee to provide an excellent account of the important features of blue phases that relate to stability, electric field effects and the influence of alignment. The paper skillfully connects work describing the blue phases in the 1980s to the research of recent years. This is a highly topical and relevant area, and the Selection Committee viewed this paper to be of highly significant interest for both fundamental and technological reasons.

In the sixth paper entitled From the discovery of the partially bilayer smectic A phase to blue phases in polar liquid crystals, Dąbrowski presents a comprehensive review of the liquid crystalline behaviour of polar liquid crystals [14]. The Review begins with George Gray’s first synthesis of the cyanobiphenyls, for which the partially bilayer smectic A phase was discovered, and continues through the properties of mixtures of polar compounds, including the induced smectic and nematic phases, and finally considers the blue phase. The review brings together a huge amount of data on both homologous series and mixtures published over several decades and presents them in a form such that the overarching picture can be clearly seen. The Selection Committee considered this masterly review will have lasting value and promote further developments in this area.

In the final paper of the shortlist enitled Flexoelectric effect and human eye perception on the image flickering of a liquid crystal display, Wu and co-workers describe the strongly detrimental effects of flexoelectricity on the electro-optical performance of fringe field-switched (FFS)-LCDs [15]. This study correlates, for the first time, experimentally determined image flicker of FFS-LCDs with human vision, dielectric properties of LC-materials and frame. The Selection Committee viewed this paper as being highly relevant and having direct impact in improving FFS-LCDs and provides valuable guidelines on how to prevent FFS-flicker.

The 2015 Prizewinning paper by Alshomrany and Clark along with the seven highly commended papers constitute an outstanding and highly diverse collection of papers, and I would strongly encourage everybody to read these articles. I would like to thank everyone who published work in Liquid Crystals during 2015 and the Selection Committee for all their hard work in selecting the 2015 Luckhurst-Samulski Prize winner.