Surface Atomic Force Microscopy Research Articles

Tuning the properties of ZnO thin film on ITO substrates with Ga dopant for dye sensitized solar cell applications

The performance of pristine and Ga doped ZnO thin films spray deposited on ITO as photoanode in dye-sensitized solar cell (DSSC) was investigated. X-ray diffraction analysis confirmed the hexagonal ZnO wurtzite phase, with preferential grains orientation along (002) plane for lower Ga concentration. Field emission scanning electron microscopy observations revealed homogeneous surface covering the entire substrate with a porous nature. Atomic force microscopy surface topography analysis indicated the deterioration of grain growth along c-axis for higher Ga doping levels. Transmission electron microscopy analysis revealed the formation of hexagonal and prismatic-shaped grains in the range 34–18 nm. Higher transmittance in the range of 85% in the visible region was obtained for 1.5 at.% Ga doped ZnO film, meanwhile the energy band gap increased with Ga doping reaching 3.46 eV. DSSC fabricated with 1.5 at.% Ga doped ZnO as photoanode and pomegranate dye as sensitizer exhibited a power conversion efficiency of 1.21%.

Elaboration and Characterization of TiO2 and Study of the Influence of The Number of Thin Films on the Methylene Blue Adsorption Rate

Thin films of titanium oxide (TiO2) deposited on glass substrates were fabricated by using the sol-gel route. The realization of these thin layers was made using the dip-coating technique with a solution of titanium isopropoxyde as a precursor. The samples prepared with different numbers of deposited layers were annealed at 400 ◦ C for 2 hours. The main purposes of this work were investigations of both the effect of the number of thin TiO2 layers on the crystal structure of the anatase form first and, their ability to adsorb the solution of methylene blue in order to make colored filters from a photocatalytic process. The deposited titanium-oxide layers were characterized by using various techniques: namely, X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM) and UV-Visible spectrometry. The result obtained by using the XRD technique showed the appearance of an anatase phase, as was confirmed by using Raman spectroscopy. The AFM surface analysis allowed the surface topography to be characterized and the surface roughness to be measured, which increased with increasing number of layers. The UV-Visible spectra showed that the TiO2 films had a good transmittance varying from 65% to 95% according to the number of layers. The gap energy varied as a function of the number of deposited layers. The as deposited TiO2 layers were tested as a photocatalyst towards the adsorption of methylene blue dye. The results obtained during this study showed that the adsorption capacity varied according to the number of deposited thin layers and the exposing duration to ultraviolet (UV) light. The maximum absorption rate of the dye was obtained for the two-layer sample. Seventy-two hours of irradiation allowed the adsorption intensity of the dye to be maximized for two-layer films.

Thermomechanically and electromagnetically actuated piezoresistive cantilevers for fast-scanning probe microscopy investigations

The self-actuating and self-sensing cantilevers make it possible to perform precise non-contact atomic force microscopy (AFM) surface investigations. The measurement and control precision in the bandwidth of up to 2 MHz is ensured by integration of the most important microscope components: the tip deflection actuator and the tip deflection detector with the spring beam. In this way the vast majority of the parasitic disturbances like resonances of a bulk piezoactuator used for the cantilever excitation are eliminated. In this paper we describe thermomechanical and electromagnetic technologies for the actuation of the cantilever vibration whose oscillation is detected using the piezoresistive deflection sensor. We present how to control the cantilever mechanics using both actuation methods. We discuss the differences in power consumption when the cantilever is actuated and what are the surface scanning features of both technologies. We show that an atomic force microscope is capable of retaining its imaging speed and resolution when its cantilever is actuated in the thermomechanical and electromagnetic way. The obtained results illustrate that the selection of the proper actuation method extends applicability of the proposed AFM technologies.

The effect of Langmuir arachidic acid layers on surface morphology and electrical properties of a polycrystalline CdS film

The effect of number of arachidic acid (AA) Langmuir layers and pH values on morphology and local electrical properties of polycrystalline cadmium sulphide (CdS) film was investigated by atomic force microscopy, electric force microscopy (EFM) and scanning Kelvin probe microscopy (SKPM). Atomic force microscopy (AFM) surface analysis showed the polycrystalline relief of CdS surface with the roughness value about 8.5 ± 0.3 nm and the drastic increases up to 25 ± 0.9 nm for semiconductor surface modified by 1, 3 and 5 AA Langmuir layers at both pH value (pH 3.6 and 8.6). Surface potential (SP) values were estimated by EFM method and showed the same sequence of changes and were equal to -1 V for CdS film and to 2.4 V and 3.5 V for 3 AA layers at pH 3.6 and 8.6, respectively. SP of 1 and 5 AA Langmuir layers was about 2 V at both pH values. Furthermore, the electrical characteristics and parameters of samples calculated by EFM quantitative method were compared with SKPM method. EFM analysis showed more pronounced SP value changes than SKPM measuring, due to mathematical value processing of the established Coulomb interaction between the probe and the sample surface.

Preparation and Characterization of Sol-gel Spin Coated Aluminum Doped Zinc Oxide (AZO) Nano Rods

Aluminum doped Zinc Oxide (AZO) nano rods with various aluminum contents were prepared by Sol-gel spin coating technique. The structural and topographical properties are studied respectively using X-Ray Diffraction (XRD) technique and Atomic Force Microscopy (AFM). Higher intensity Zinc Oxide (ZnO) peak (002) is observed in 1at.% Aluminum doped nano rods with 50Sec spin coated sample underwent 300°C of annealing temperature. Morphologic, Compositional and Crystallographic information of samples are predicted using Transmission Electron Microscopy (TEM), the 600 nm long nano rods with an aspect ratio of 10 is obtained for 20 Sec and 50 Sec spin coating time. The AFM surface topography (2D & 3D images) of 1 at% aluminum doped nano rods exhibits a porous microstructure and the spherical crystalline particle size of approximately 24 ± 15 nm.

Synthesis and sonocatalytic performance of a ternary magnetic MIL-101(Cr)/RGO/ZnFe2O4 nanocomposite for degradation of dye pollutants

In this study, new ternary magnetic MIL-101(Cr)/RGO/ZnFe2O4 catalyst (with 30% wt of ZnFe2O4) was synthesized via a hydrothermal route for sonodegradation of organic dyes. The structural, optical and magnetic properties of the nanocomposite were detected by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–visible), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, vibrating sample magnetometer (VSM), atomic force microscopy (AFM), Raman spectroscopy and BET surface area analysis. To evaluate the sonocatalytic activity of the as-prepared MIL-101(Cr)/RGO/ZnFe2O4 nanocomposite, the H2O2-assisted degradation of organic dyes such as congo red (CR), methylene blue (MB), Rhodamine B (RhB) and methyl orange (MO) in aqueous solution was studied under ultrasound irradiation. The obtained results indicated that the ternary MIL-101(Cr)/RGO/ZnFe2O4 nanocomposite had better performance for sonodegradation of these dyes than MIL-101(Cr)/RGO, pure MIL-101(Cr) or ZnFe2O4. The enhanced sonocatalytic performance of the as-prepared ternary nanocomposite could be attributed to the fast generation and separation of charge carriers (electrons and holes) in ZnFe2O4and MIL-101(Cr) and their transfer to the surface of graphene sheets. Moreover, the relatively high specific surface area of the MIL-101(Cr)/rGO and magnetic property of ZnFe2O4 improve the degradation efficiency of the dyes. The recovery of the ternary magnetic sonocatalyst from treated water could be easily achieved using an external magnetic field. The main influence factors on the sonocatalytic activity such as catalyst dosage and dye initial concentration were also investigated. The trapping experiments indicated that OH radicals are the prominent active species in dye degradation. In addition, the reusability test, was also carried out to ensure the stability of the employed sonocatalyst.

Modelling of diffusion behavior of ions in low-density and high-density calcium silicate hydrate

To investigate the relationship between morphology and specific ion transport properties in low-density (LD) and high-density (HD) calcium-silicate-hydrate (C-S-H), a numerical method of directly achieving diffusivities is developed. Firstly, a multiscale structural model is proposed to reconstruct C-S-Hs in which self-similarity and quantitative physical properties are compared to experimental results. Subsequently, electrical double layer (EDL) theory is introduced into analysis of ion transport in pore solution. The quantitative analysis of various influence factors of EDL on ion diffusivities in pore solution is carried out and average diffusivity in pore solution is also obtained. Moreover, a numerical method for solving Fick’s first law equation is performed on the simulated C-S-H structures to obtain numerous diffusivities of common ions in C-S-H. Finally, the significant parameter for durability in reinforcement concrete, chloride diffusivity in hardened cement paste, is predicted using simulated diffusivities in C-S-Hs, based on a multiscale method. It is found that compared to the atomic force microscope image and surface area of C-S-H, this self-similar model can well reconstruct real C-S-H structures. In addition, the influence factors of EDL including overlapping diffuse layer, relative potential, cation/anion, valence, zeta potential and bulk solution have great effects on ion diffusivities, which demonstrates EDL effects cannot be ignored when investigating ion transport behavior in C-S-H. Furthermore, using an appropriate case of pore solution with diffusivities of 8.2×10−12m2/s in LD C-S-H and 2.0×10−13m2/s in HD C-S-H, estimated chloride diffusivities in cement pastes agree well with measured values, which can indirectly indicate this modelling work is reasonable.

Contact atomic force microscopy using piezoresistive cantilevers in load force modulation mode

Scanning probe microscopy (SPM) encompasses several techniques for imaging of the physical and chemical material properties at nanoscale. The scanning process is based on the detection of the deflection of the cantilever, which is caused by near field interactions, while the tip runs over the sample's surface. The variety of deflection detection methods including optical, piezoresistive, piezoelectric technologies has been developed and applied depending on the measurement mode and measurement environment. There are many advantages (compactness, vacuum compatibility, etc.) of the piezoresistive detection method, which makes it very attractive for almost all SPM experiments. Due to the technological limitations the stiffness of the piezoresistive beams is usually higher than the stiffness of the cantilever detected using optical methods. This is the basic constraint for the application of the piezoresistive beams in contact mode (CM) atomic force microscopy (AFM) investigations performed at low load forces (usually less than 20 nN). Drift of the deflection signal, which is related to thermal fluctuations of the measurement setup, causes that the microscope controller compensates the fluctuations instead of compensating the strength of tip-surface interactions. Therefore, it is quite difficult to keep near field interaction precisely at the setpoint level during the whole scanning process. This can lead to either damage of the cantilever's tip and material surface or loosing the contact with the investigated sample and making the measurement unreliable.For these reasons, load force modulation (LoFM) scanning mode, in which the interaction at the tip is precisely controlled at every point of the sample surface, is proposed to enable precise AFM surface investigations using the piezoresistive cantilevers. In this article we describe the developed measurement algorithm as well as proposed and introduced hardware and software solutions. The results of the experiments confirm strong reduction of the AFM entire setup drift. The results demonstrating contactless tip lateral movements are presented. It is common knowledge that such a scanning reduces tip wear.

Chitosan: A macromolecule as green corrosion inhibitor for mild steel in sulfamic acid useful for sugar industry

The present investigation aims at investigation of low cost nontoxic carbohydrate biopolymer chitosan as corrosion inhibitor alone and in combination with KI for mild steel in 1M sulfamic acid medium using gravimetric, electrochemical and surface analysis techniques. It is found that chitosan alone exhibits inhibition efficiency of 73.8% at 200ppm concentration. However, in combination with KI (5ppm), it gave more than 90% inhibition efficiency. The significant increase in the inhibition performance of chitosan has been explained by the synergistic mechanism. The results of Potentiodynamic polarization study shows that chitosan and its blend with KI decreases both anodic and cathodic reactions occurring at mild steel surface in 1M sulfamic acid medium by blocking active sites of the metal and acts as mixed type inhibitor. EIS study reveals that the polarization resistance increases with increase in the concentration of inhibitors which increases charge transfer resistance across the metal/solution interface. The adsorption of chitosan followed the Langmuir adsorption isotherm. The formation of inhibitor film on metal surface was supported by scanning electron microscopy (SEM) and atomic force microscopy (AFM) surface studies.

Effect of ablation laser pulse repetition rate on the surface protrusion density of hydroxyapatite thin films deposited using pulsed laser deposition

The effect of the pulse repetition rate of the ablation laser on surface protrusion density was investigated for hydroxyapatite thin films deposited using pulsed laser deposition. Atomic force microscope surface images showed a marked decrease in surface protrusion density at lower pulse repetition rate, while protrusion-free areas exhibited similar morphologies independent of the pulse repetition rate. These results indicate that the surface protrusions were not formed or enlarged from surface migration of atomic species on the surface, which formed the smooth surface of the protrusion-free area. The postulated origin of the protrusions was large particles or droplets produced directly from the target irradiated with the ablation laser. These results suggest that the optimum pulse repetition rate for protrusion-free hydroxyapatite thin film surfaces is ≤3Hz.

Poly (m-chloroaniline) and poly (1-naphthylamine) based conjugated polymer for enhanced fluorescence imaging in diverse cell types

Fluorescent probes, based on doped polyaniline, poly(m-chloroaniline) and poly(1-naphthylamine) have been tailored for in vitro cell imaging application. Its structure was characterized by FTIR, UV–visible, fluorescence, atomic force microscopy and BET surface area analysis. The intensity of fluorescence in poly(m-chloroaniline) and poly(1-naphthylamine) was much stronger compared to polyaniline alone. The optimal emitting properties of poly(m-chloroaniline), poly(1-naphthylamine) and polyaniline were related to both structure and shape of the particle and behave according to concentration dependent manner. The poly(m-chloroaniline) and polyaniline emits greenish blue color while poly(1-naphthylamine) exibits intense red and greenish blue color emission respectively. Poly(m-chloroaniline) and poly(1-naphthylamine) demonstrate highly enhanced signals for fluorescence based cell imaging in K-562, U2-OS and MCF-7 cells. Above compounds are cytocompatible, and with no significant loss of viability in K-562, U2-OS and MCF-7 cells following treatment. Higher concentration of the material however, causes moderate loss in viability of the cell besides inducing cytotoxicity. Luminescent micro particles of doped poly(m-cholroaniline) and poly(1-naphthylamine) showed significant potential for biological and diagnostic application.

Study of hydrogen implantation-induced blistering in GaSb for potential layer transfer applications

GaSb samples were implanted by 100 keV hydrogen ions (H+) at room temperature with fluence values of 1 × 1017 and 2 × 1017 ions cm−2. Post-implantation annealing studies revealed that the samples implanted with a fluence of 2 × 1017 ions cm−2 did not show blistering/exfoliation. For the lower fluence, the samples showed the formation of surface blisters/craters along with the large area exfoliation of the top H-implanted surface. Topographical investigations of the samples were carried out using Nomarski optical microscopy, atomic force microscopy and stylus surface profilometry. The lateral sizes and heights of the blisters varied between 2–5 µm and 5–20 nm respectively. The root mean square roughness of the exfoliated region was about 12 nm while the exfoliation depth was found to be 730 nm. The exfoliation depth in the H-implanted GaSb is close to the damage concentration peak as found from SRIM calculations. The Föppl–von Karman theory of thin plates has been used to understand the effect of internal pressure and stress on the surface blistering. Using the above mentioned implantation and annealing parameters, potential layer transfer of GaSb could be enabled.

Differences in the nanoscale electrical properties of GaN films grown on sapphire and ZnO substrates by molecular beam epitaxy.

Gallium nitride (GaN) films were grown on sapphire and zinc oxide (ZnO) single crystal substrates using plasma-assisted molecular beam epitaxy. As ZnO for GaN have a better lattice match, the coverage ratio of the GaN (002) plane on the ZnO substrate was significantly higher by about 45%. According to conducting atomic force microscopy and scanning surface potential microscopy measurements, the surface of GaN films grown on the ZnO substrate had two excellent physical characteristics: (a) an 18% reduction of the high contact current region, and (b) a highly uniform work function distribution. Therefore, for future applications in GaN-based light-emitting diodes, the use of ZnO as a substrate will prolong the luminescence lifetime and enhance the luminescent monochromaticity.

Heterobifunctional Polyprotein for Efficient Characterization of Mechanically Labile Proteins

Atomic force microscopy (AFM) is a powerful tool for single molecule force spectroscopy, allowing researchers to directly probe the energy landscape of protein folding and unfolding. Despite the power of this technique, it has been hindered by non-specific attachment of protein to the AFM surface and tip. Non-specific attachment allows for simple experimental set up, but results in low attachment efficiency, multiple attachments, incomplete unfolding, and adhesion to the surface which can mask low force unfolding events. Not only does this make data collection incredibly time consuming, it also makes it difficult to test mechanically labile proteins. Despite recent advances in tip and surface functionalization, protein labeling continues to be a major hurdle for many labs. Furthermore, most current labeling protocols require cysteine tag modification which is unsuitable for cysteine containing proteins. To address this issue, we developed a simple and versatile protein cassette utilizing aldehyde tags to facilitate the specific attachment of proteins to both the AFM surface and tip. Combining our labeled protein cassette with newly developed techniques to functionalize the surface and tip resulted in a 75-fold increase in attachment efficiency while greatly reducing the number of incomplete unfolding events and surface adhesion. We have shown the ability to quickly insert new proteins into our cassette and rapidly characterize their response to force. Moreover, we were able to rapidly collect a dynamic force spectrum for α3D, an α-helical protein which unfolds at very low force. Our protein cassette is a powerful tool that not only increases the efficiency of AFM based single molecule force spectroscopy, but also enhances the ability to test mechanically labile proteins.

AFM and SIMS surface and cation profile investigation of archaeological obsidians: New data

Abstract Obsidian surface roughness and rind structure both play a major influence on the Obsidian Hydration Dating (OHD). AFM (Atomic Force Microscopy) investigation coupled with quadrupole SIMS hydrogen data profiles establish a validation criterion of quantitative evaluation of roughness for OHD dating purposes. More evidence of the importance of the surface morphology at the nanoscale is given for five obsidian tools of different origin. The latter relates to the dynamic ion influx diffusion kinetics between surface and surrounded sediment media, and the obsidian structure, thus, 2D and 3D surface mapping, as well as, cation profiling (H, C, Mg, Al, F, S, Cl, CN, O isotopes) were made by TOF-SIMS and quad-SIMS. It was found that the C and Mg are considered as imposed criteria for accepting suitability of H + profiles for further processing by SIMS-Surface Saturation dating method. The effect of roughness to dating is discussed.

Investigation on the effect of phase segregation on the mechanical properties of polymer modified bitumen using analytical and morphological tools

The mechanical strength of polymer modified bituminous mix which is evaluated in terms of stiffness reflects the deformation behaviour of bituminous mixture. The stiffness of the binder strongly depends on its chemical composition besides aggregate structure of the bituminous mixture. Compatibility of polymer with the base bitumen is considered as major strength enhancing factor in the case of polymer modified bituminous mix. To relate the factors affecting the mechanical strength of the binder a new approach in this research study was adopted in order to relate the compatibility of 80/100 pen bitumen with polymer Polypropylene (PP) using analytical and morphological tools. Morphological tools like Atomic Force Microscopy (AFM) and Transmission Electron Microscope (TEM) were used to study the changes due to the difference in compatibility of polymer with bitumen. It was observed that the presence of phase segregated layer as observed by AFM surface morphology was considered as the main strength enhancing factor of the bituminous mix. While the presence of lamella as observed in TEM scanned images of PP PMB revealed that addition of polymer forms localized network in the phase segregated layer which induces the stiffening effect in PMB. From the chromatographic method (SARA) analytical analysis Saturate, Aromatics, Resin and Asphaltene fractionate were determined in the blend. It was observed that chemical composition of the blend also has a profound effect on the rheological properties and on the morphology of polymer modified bituminous (PMB) blend. It was concluded that PP PMB gets benefited by phase segregated layer in the blend when the polymer concentration was kept below 3% as it sufficiently enhances the mechanical strength of the PMB binder as observed by dynamic creep results.

Fluorinated zirconia-based sol-gel hybrid coatings on polycarbonate with high durability and improved scratch resistance

Hard, scratch-resistant and transparent fluoropolymer-based hybrid coatings are successfully prepared through the sol-gel chemistry and investigated, in the attempt to correlate the chemical, physical and surface properties of these materials with the mechanical properties (i.e. hardness and elastic modulus) measured at the nanoscale by atomic force microscopy (AFM). The organic component of these coatings consists in a hydroxyl-functional fluoropolymer resin, which belongs to the class of chlorotrifluoroethylene-vinylether copolymers and exhibits remarkable properties such as easy handling, great weather resistance, good adhesion and flexibility of coatings. A functionalization of this copolymer is also performed using an isocyanate-functionalized silane in order to assure a covalent cross-linking of organic fluorinated resin with inorganic phases. The combination of the silanized chlorotrifluoroethylene-vinylether copolymer with different sols composed of silica and zirconia is used to obtain high scratch resistance and high durability coatings on polycarbonate. A series of three hybrid coatings with different zirconia/silica molar ratios (0.09/0.48) are developed and analyzed by differential scanning calorimetry (DSC), water contact angle measurements, pencil hardness and adhesion tests. AFM scratch hardness, coating wettability and surface composition measured by Fourier transform infrared spectroscopy (FTIR) are regularly monitored over long-term UV–vis light exposure, to assess the durability of the hybrid coatings. Interestingly, the hybrid fluorinated coatings exhibit an improved scratch resistance and a superior long-term stability when exposed to an accelerated weathering, compared to pristine PC substrates. The mixed silica/zirconia hybrid coatings with a low and intermediate zirconia-to-silica ratio also show excellent mechanical strength, high level of hardness and superior integrity after long-term light exposure.

Effect of Firing Temperature on Electrical and Structural Characteristics of Screen Printed In2O3 Thick Films

In2O3 thick films were prepared on porous alumina (Al2O3) substrate by using standard screen printing technique and fired at different temperatures from 750ºC to 950ºC in air atmosphere. The DC resistance of film was measured by half bridge method in air atmosphere at different temperatures. The films were showing decrease in resistance with increase in temperature indicating semiconductor behavior. The resistivity (ρ), activation energy (∆E) and temperature coefficient of resistance (TCR) are evaluated at different firing temperatures. Samples were characterized by Xray diffraction (XRD) technique, scanning electron Microscopy (SEM)), Energy Dispersive Spectroscopy (EDX) and Atomic force microscopy (AFM) technique, for compositional, phase confirmation and surface growth and morphology study.

Plasmonic nano-protrusions: hierarchical nanostructures for single-molecule Raman spectroscopy

Classical methods for enhancing the electromagnetic field from substrates for spectroscopic applications, such as surface-enhanced Raman spectroscopy (SERS), have involved the generation of hotspots through directed self-assembly of nanoparticles or by patterning nanoscale features using expensive nanolithography techniques. A novel large-area, cost-effective soft lithographic technique involving glancing angle deposition (GLAD) of silver on polymer gratings is reported here. This method produces hierarchical nanostructures with high enhancement factors capable of analyzing single-molecule SERS. The uniform ordered and patterned nanostructures provide extraordinary field enhancements that serve as excitatory hotspots and are herein interrogated by SERS. The high spatial homogeneity of the Raman signal and signal enhancement over a large area from a self-assembled monolayer (SAM) of 2-naphthalenethiol demonstrated the uniformity of the hotspots. The enhancement was shown to have a critical dependence on the underlying nanostructure via the surface energy landscape and GLAD angles for a fixed deposition thickness, as evidenced by atomic force microscopy and scanning electron microscopy surface analysis of the substrate. The nanostructured surface leads to an extremely concentrated electromagnetic field at sharp nanoscale peaks, here referred to as ‘nano-protrusions’, due to the coupling of surface plasmon resonance (SPR) with localized SPR. These nano-protrusions act as hotspots which provide Raman enhancement factors as high as 108 over a comparable SAM on silver. Comparison of our substrate with the commercial substrate Klarite™ shows higher signal enhancement and minimal signal variation with hotspot spatial distribution. By using the proper plasmon resonance angle corresponding to the laser source wavelength, further enhancement in signal intensity can be achieved. Single-molecule Raman spectra for rhodamine 6G are obtained from the best SERS substrate (a GLAD angle of 60°). The single-molecule spectrum is invariant over the substrate, due to the patterned ordered nanostructures (nano-protrusions).

Deposition of Ultrathin Nano-Hydroxyapatite Films on Laser Micro-Textured Titanium Surfaces to Prepare a Multiscale Surface Topography for Improved Surface Wettability/Energy.

The primary aim of this study was to analyse the correlation between topographical features and chemical composition with the changes in wettability and the surface free energy of microstructured titanium (Ti) surfaces. Periodic microscale structures on the surface of Ti substrates were fabricated via direct laser interference patterning (DLIP). Radio-frequency magnetron sputter deposition of ultrathin nanostructured hydroxyapatite (HA) films was used to form an additional nanoscale grain morphology on the microscale-structured Ti surfaces to generate multiscale surface structures. The surface characteristics were evaluated using atomic force microscopy and contact angle and surface free energy measurements. The structure and phase composition of the HA films were investigated using X-ray diffraction. The HA-coated periodic microscale structured Ti substrates exhibited a significantly lower water contact angle and a larger surface free energy compared with the uncoated Ti substrates. Control over the wettability and surface free energy was achieved using Ti substrates structured via the DLIP technique followed by the deposition of a nanostructured HA coating, which resulted in the changes in surface chemistry and the formation of multiscale surface topography on the nano- and microscale.