The 2022 Luckhurst-Samulski Prize

The Luckhurst-Samulski Prize was launched in 2009 [1] and the first 13 winners are listed in Table 1. The 2021 Luckhurst-Samulski Prize was presented earlier this year to the successful authors, Atsutaka Manabe, Martin Kraska and Matthias Bremer, for their paper entitled Ferroelectric nematic phase at and below room temperature [14], at the 49^th German Liquid Crystal Conference (Figure 1). This was the first occasion that the Prize has been awarded to a group based in industry.

Figure 1. (Colour online) Corrie Imrie presenting the 2021 Luckhurst-Samulski Prize to Atsutaka Manabe, Martin Kraska and Matthias Bremer at the 49^th German Liquid Crystal Conference held in Stuttgart (March 2023).

Table 1. Previous winners of the Luckhurst-Samulski Prize and their authors.

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 SE, 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, Frascescangeli 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 flow.	[6]
2014	Takezoe H, Araoka, F.	Polar columnar liquid crystals.	[7]
2015	Alshomrany A, Clark NA.	Fisheye lens conoscopy.	[8]
2016	Dawood AA, Grossel MC, Luckhurst GR, Richardson RM, Timimi BA, Wells NJ, Yousif YZ.	On the twist-bend nematic phase formed directly from the isotropic phase.	[9]
2017	Paterson DA, Abberly JP, Harrison WT, Storey JM, Imrie CT.	Cyanobiphenyl-based liquid crystal dimers and the twist-bend nematic phase.	[10]
2018	Tschierske C.	Mirror symmetry breaking in liquids and liquid crystals.	[11]
2019	Cruickshank E, Salamonczyk M, Pocieha D, Strachan GJ, Storey JMD, Wang C, Feng J, Zhu CH, Gorecka E, Imrie CT.	Sulfur-linked cyanobiphenyl-based liquid crystal dimers and the twist-bend nematic phase.	[12]
2020	Abberley JP, Walker R, Storey JMD, Imrie CT.	Molecular structure and the twist-bend nematic phase: the role of terminal chains	[13]
2021	Manabe A, Bremer M, Kraska M.	Ferroelectric nematic phase at and below room temperature	[14]

The Prize is named after the Founding Editors of the journal Liquid Crystals, Geoffrey Luckhurst and Ed Samulski, and is awarded to the best paper published in that year in the Journal. The challenging task of selecting the winner from around 250 articles published each year is left to the Prize’s Selection Committee consisting of the Journal’s Editorial Board and myself as Editor. The process begins with our referees who are asked if they have reviewed a paper that would make a worthy winner of the Prize. These recommendations are collated and shared with the Selection Committee to assist in its role to draw up a longlist of nominations from which the eventual winner will be chosen. Each member can nominate as many, or as few papers as they wish from the referees’ recommendations and any other paper published that year. The papers that garner the most nominations in this stage form the shortlist to be voted upon by the members of the Selection Committee. Any member that has a paper on the shortlist is exempted from the final stage of the selection process.

The shortlist for the 2022 Luckhurst-Samulski Prize consisted of seven papers, and any one of these would have made an excellent Prizewinner. I am delighted to announce that the 2022 Luckhurst-Samulski Prize has been awarded to Carsten Tschierske for his paper entitled The Magic 4-Cyanoresocinols-Their Role in the Understanding of Phenomena at the Rod-Banana Cross-Over and Relations to Twist-Bend Phases and Other Newly Emerging LC Phase Types [15]. In this overview, Carsten describes the behaviour of bent-core systems containing the polar cyano-group with a particular focus on the extensively studied 4-cyanoresorcinol bisbenzoates. This is a comprehensive and insightful review in which many emerging areas of liquid crystal science are discussed including cybotaxis and biaxiality. A particular focus is given to the formation and structures of the heliconical or twist-bend smectic phases. The Selection Committee noted that this erudite contribution to our field will undoubtedly stand the test of time and will benefit the community for many years to come. This is the second time that Carsten has been awarded the Luckhurst-Samulski Prize, the first being in 2018 for his paper entitled Mirror symmetry breaking in liquids and liquid crystals [11].

The recently discovered ferroelectric nematic phase is probably the hottest topic in the field of liquid crystals and all six remaining papers on the short-list focussed on this topic. Each was highly commended by the Selection Committee and most certainly warrant recognition here. In strict chronological order of publication, the first of these six highly commended papers was by César Luis Folcia, Josu Ortega, Raul Vidal, Teresa Sierra and Jesús Etxebarria, entitled The ferroelectric nematic phase: an optimum liquid crystal candidate for nonlinear optics [16]. In this paper, the authors argue that ferroelectric nematogens have the very real application potential to underpin the next generation of nonlinear optical devices. They show that RM734 has one of the largest d₃₃ coefficients reported for a ferroelectric liquid crystal even though its molecular structure has not been designed with this application in mind. The Selection Committee commented that this paper highlights the exciting application potential of this new class of liquid crystals.

The next shortlisted paper is entitled Ideal mixing of paraelectric and ferroelectric nematic phases in liquid crystals of distinct molecular species by Xi Chen, Zhecong Zhu, Mitchell Magrini, Eva Korblova, Cheol Park, Matthew Glaser, Joseph Maclennan, David Walba and Noel Clark [17]. In this work, the authors construct the binary phase diagram for the two prototypical ferroelectric nematogens, DIO and RM734, and this shows complete miscibility between the two components across the whole composition range. This reveals that the paraelectric and ferroelectric nematic phases are the same for both compounds. This ideal mixing is attributed in part to their similar molecular shapes and net longitudinal dipole moments and to their common tendency for head-to-tail molecular association. By comparison, the two compounds show poor solubility in the crystal phases. The Selection Committee noted that this work is particularly significant in underpinning our understanding of the physics of the ferroelectric nematic phase.

The third of these papers by Rony Saha, Pawan Nepal, Chenrun Feng, Md Sakhawat Hossain, Masafumi Fukuto, Ruipeng Li, James Gleeson, Samuel Sprunt, Robert Twieg and Antal Jákli entitled Multiple ferroelectric nematic phases of a highly polar liquid crystal compound [18] describes the synthesis and characterisation of a new ferroelectric nematogen, RT11001. The authors report that RT11001 shows three distinct ferroelectric phases. The highest temperature of these is a polar nematic fluid containing non-polar smectic polar clusters. On cooling, this forms a polar nematic phase with polar smectic clusters. The lowest temperature phase is assigned as a biaxial polar nematic phase. The Selection Committee commented that this represented a novel contribution to the rapidly emerging field of ferroelectric nematic liquid crystals of very significant interest at both fundamental and technological levels.

The next paper of the shortlist by Richard Mandle entitled Supramolecular ferroelectric nematic materials [19] describes the first examples of ferroelectric nematogens assembled via hydrogen bonding. These complexes are structurally analogous to RM734 in which the 4-nitrophenyl unit has been replaced by 4-nitropyridyl. The observation of ferroelectric nematic behaviour by these complexes is surprising given that their dipole moments are relatively small, and the author suggests that the observed behaviour may be attributed, at least in part, to the alternating regions of positive and negative electric charge. The Selection Committee considered this to be a novel and significant contribution to our understanding of structure–property relations in this new class of liquid crystals and will inspire many related works concerning the molecular design of ferroelectric nematogens.

The penultimate paper in this collection is by Huaqian Long, Jinxing Li, Mingjun Huang and Satoshi Aya and entitled Mixing-induced phase stabilization and low-temperature-shifting of ferroelectric nematics [20]. In this report, the authors show that by mixing ferroelectric nematogens, the resulting materials may be designed not only to exhibit the ferroelectric nematic phase at room temperature but also that these mixtures show enhanced second harmonic generation and dielectric properties than their constituent components. The Selection Committee considered this to be a very significant contribution to the development of ferroelectric nematic materials amenable to fundamental study and also for prototyping new electrooptic devices.

The final shortlisted paper was a second contribution from the groups in Bilbao and Zaragoza. The paper by Josu Ortega, César Luis Folcia, Jesús Etxebarria and Teresa Sierra entitled Ferroelectric chiral nematic liquid crystals: new photonic materials with multiple bandgaps controllable by low electric fields [21] describes a spectroscopic study of a mixture of the ferroelectric nematogen RM734 with a chiral non-polar compound. This exhibits two chiral nematic phases, the conventional N* phase and the polar N_F* phase that show very different behaviour under the influence of an electric field. The authors argue that the N_F* phase behaves as a photonic material with multiple gaps tuneable by small fields. The Selection Committee considered that these important observations are now applicable to a range of new electro-optic applications.

The Prizewinning article is made free to access, and several of the short-listed papers have been published as open access. I would strongly encourage you all to read this collection of papers. They are beautifully written and describe research at the very leading edge of our field. On average, each has been viewed over one thousand times. I would like to thank everyone who published their work in Liquid Crystals during 2022 and the Selection Committee for all their hard work in selecting the 2022 Luckhurst-Samulski Prizewinner. The selection process for the 2023 Prize begins very soon!