Plasma Immersion Ion Implantation Research Articles

Evaluation of osseointegration of plasma treated polyaryletherketone maxillofacial implants

Osseointegration is a crucial property of biomaterials used for bone defect repair. While titanium is the gold standard in craniofacial surgeries, various polymeric biomaterials are being explored as alternatives. However, polymeric materials can be bioinert, hindering integration with surrounding tissues. In this investigation, plasma ion immersion implantation (PIII)-treated polyether ether ketone (PEEK) and polyether ketone (PEK) implants were assessed in a sheep maxilla and mandible model. Defects were filled with PIII-treated PEEK and PEK implants, produced through fused filament fabrication (FFF) and selective laser sintering (SLS), respectively. Positive controls were grade 23 titanium implants via selective laser melting, while untreated PEEK implants served as negative controls. Surface analyses using scanning electron microscopy and atomic force microscopy revealed favorable properties. Osseointegration was qualitatively and quantitatively assessed at 8-, 10-, and 12-weeks post-implantation, showing significantly improved outcomes for both PIII-treated PEEK and PEK implants compared to untreated controls. The study suggests PIII treatment enhances FFF-printed PEEK’s osseointegration, and PIII-treated SLS-printed PEK achieves comparable osseointegration to 3D printed titanium. These findings underscore surface modification strategies’ potential for polymeric biomaterials, offering insights into developing alternative implant materials for craniofacial surgeries, with enhanced biocompatibility and osseointegration capabilities for improved clinical outcomes.

Thermal Evolution of Expanded Phases Formed by PIII Nitriding in Super Duplex Steel Investigated by In Situ Synchrotron Radiation

The Plasma Immersion Ion Implantation (PIII) nitriding was used to form a modified layer rich in expanded austenite (γN) and expanded ferrite (αN) phases in super duplex steel. The thermal stability of these phases was investigated through the in situ synchrotron X-ray diffraction. All the surfaces were analyzed by SEM, EDS, and nanoindentation. During the heating stage of the thermal treatments, the crystalline structure of the γN phase expanded thermally up to a temperature of 350 °C and, above this temperature, a reduction in the lattice parameter was observed due to the diffusion of nitrogen into the substrate. During the isothermal heating, the gradual diffusion of nitrogen continued and the lattice parameter of the γN phase decreased. Increasing the treatment temperature from 450 °C to 550 °C, a greater reduction in the lattice parameter of the γN phase occured and the peaks related to the CrN, α, and αN phases became more evident in the diffractograms. This phenomenon is associated with the decomposition of the γN phase into CrN + α + αN. After the heat treatments, the thickness of the modified layers increased and the hardness values close to the surface decreased, according to the diffusion of the nitrogen to the substrate.

Effects of plasma surface modification of Mg-2Y-2Zn-1Mn for biomedical applications

Magnesium (Mg) alloys have emerged as promising materials for biodegradable implants in orthopedic, oral, and cardiovascular applications. Despite their potential, high corrosion rate, and release of diatomic hydrogen in the surrounding environment remain the unmet challenges. In this research, oxygen plasma ion immersion implantation (O-PIII) was investigated in an attempt to modify the degradation rate of Mg-2Y-2Zn-1Mn alloy. In particular, the effects of pulse duration (tpd) and pressure (p) on the degradation rate were investigated. For all the investigated conditions, plasma treatment enriched the surface chemical composition with O, forming a Mg- and Y- rich oxide layer. Mg and Y elements were mainly concentrated at grain boundaries. The concurrent phenomena of sputtering and energetic implantation led to crystalline Y2O3 formation. Electrochemical investigations confirm that the degradation rate of samples decreased significantly, from ∼0.23 mm/y for untreated to ∼0.07 mm/y for O-PIII conditions. These findings demonstrate the effectiveness of O-PIII in changing surface properties and controlling corrosion rate of Mg alloys.

Corrosion resistance and biocompatibility of carbon ion implanted AZ31B magnesium alloy

The poor corrosion resistance of magnesium limits its clinical applications. Accordingly, in the present study, carbon ions were incorporated into a AZ31b magnesium alloy surface via carbon plasma immersion ion-implantation to improve its corrosion resistance and biocompatibility. The surface morphology and properties of the modified alloy were evaluated by field-emission scanning electron microscopy, water contact angle measurement, Raman scattering, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy. Furthermore, compositional depth profiles were obtained by glow discharge optical emission spectroscopy, revealing a Gaussian-like distribution of carbon concentration. Electrochemical and hydrogen-evolution analysis demonstrated the successfully improved corrosion resistance of the AZ31b Mg alloy, while its biocompatibility was demonstrated by MTT and cell-adherence assays.

Influence of bias voltage rise time, pressure and magnetic field on the boundary layer time evolution of a thermal collisional magnetized plasma in plasma immersion ion implantation

Influence of bias voltage rise time, pressure and magnetic field on the boundary layer time evolution of a thermal collisional magnetized plasma in plasma immersion ion implantation

Effect of N plasma immersion ion implantation (N-PIII) on the microstructure and mechanical properties of 8Cr4Mo4V steel

To enhance the surface hardness and wear resistance of 8Cr4Mo4V steel, nitrogen plasma immersion ion implantation (N-PIII) was carried out, under various nominal implantation energies, in this study. Additionally, the microstructure and mechanical properties of the steel were analyzed. The results indicated that the depth of the nitrogen ion-implanted layer escalated with the specified implantation energy, reaching 140 nm for a 50 keV sample. Nitrogen was present within the implanted layer in the martensite lattice as a solute, and also in the form of nitrides along with alloying elements. Moreover, a nanocrystalline layer approximately 40–70 nm thick also formed at the sample surface. As the implantation energy increased, both the surface roughness and residual stress of the sample initially increased before declining, whereas the surface hardness and modulus exhibited a gradual increase. After the 50 keV N-PIII treatment, the surface hardness of the sample increased by 39 %, which caused a remarkable reduction in the friction coefficient, and the wear amount was also reduced by about 40 %. This work systematically establishes the relationship between the surface microstructures, surface morphology, and mechanical properties of implanted 8Cr steel, and significantly improves its surface hardness and wear resistance.

The effects of different anode manufacturing methods on deep levels in 4H-SiC p+n diodes

The manufacture of bipolar junctions is necessary in many 4H-SiC electronic devices, e.g., junction termination extensions and p+in diodes for voltage class >10 kV. However, the presence of electrically active levels in the drift layer that act as minority charge carrier lifetime killers, like the carbon vacancy (VC), undermines device performance. In the present study, we compared p+n diodes whose anodes have been manufactured by three different methods: by epitaxial growth, ion implantation, or plasma immersion ion implantation (PIII). The identification of the electrically active defects in the drift layers of these devices revealed that a substantial concentration of VC is present in the diodes with epitaxial grown or ion implanted anode. On the other hand, no presence of VC could be detected when the anode is formed by PIII and this is attributed to the effects of strain in the anode region. Our investigation shows that PIII can be a useful technique for the manufacture of bipolar devices with a reduced concentration of lifetime killer defects.

A biocompatible nanofibers modified by plasma for osteoblast growth differentiation.

This work employs nitrogen plasma immersion ion implantation (PIII) to modify electrospinning polylactic acid membranes and immobilizes essential fibroblast growth factors(bFGF) by forming cross-linking bonds. The study investigates the modified membranes' surface characteristics and the stimulatory effects of cross-linked bFGF polylactic acid membranes on osteoblast and fibroblast proliferation. The PIII process occurs under low vacuum conditions and is controlled by processing time and power pulse width. The experimental results indicate that, within a 400-second N2-PIII treatment, the spun fibers remain undamaged, demonstrating an increase in hydrophilicity (from 117° to 38°/36°) and nitrogen content (from 0% to 7.54%/8.05%). XPS analysis suggests the formation of a C-N-C=O cross-linked bond. Cell culture and activity assessments indicate that the PIII-treated and cross-linked bFGF film exhibits significantly higher cell growth activity (P<0.05) than the untreated group. These intergroup differences are attributed to the surface cross-linking bond content. In osteogenic induction, the results for each day show that the treated group performs better. However, the intergroup disparities within the cross-linked bFGF group disappear with prolonged culture time due to the rapid osteogenesis prompted by bFGF. The findings suggest that PIII treatment of electrospinning polylactic acid membranes holds promise in promoting osteogenesis in bone tissue scaffolds.

Setting Plasma Immersion Ion Implantation of Ar+ Parameters towards Electroforming-Free and Self-Compliance HfO2-Based Memristive Structures.

Memristive structures are among the most promising options to be components of neuromorphic devices. However, the formation of HfO2-based devices in crossbar arrays requires considerable time since electroforming is a single stochastic operation. In this study, we investigate how Ar+ plasma immersion ion implantation (PI) affects the Pt/HfO2 (4 nm)/HfOXNY (3 nm)/TaN electroforming voltage. The advantage of PI is the simultaneous and uniform processing of the entire wafer. It is thought that Ar+ implantation causes defects to the oxide matrix, with the majority of the oxygen anions being shifted in the direction of the TaN electrode. We demonstrate that it is feasible to reduce the electroforming voltages from 7.1 V to values less than 3 V by carefully selecting the implantation energy. A considerable decrease in the electroforming voltage was achievable at an implantation energy that provided the dispersion of recoils over the whole thickness of the oxide without significantly affecting the HfOXNY/TaN interface. At the same time, Ar+ PI at higher and lower energies did not produce the same significant decrease in the electroforming voltage. It is also possible to obtain self-compliance of current in the structure during electroforming after PI with energy less than 2 keV.

A Preclinical Trial Protocol Using an Ovine Model to Assess Scaffold Implant Biomaterials for Repair of Critical-Sized Mandibular Defects.

The present work describes a preclinical trial (in silico, in vivo and in vitro) protocol to assess the biomechanical performance and osteogenic capability of 3D-printed polymeric scaffolds implants used to repair partial defects in a sheep mandible. The protocol spans multiple steps of the medical device development pipeline, including initial concept design of the scaffold implant, digital twin in silico finite element modeling, manufacturing of the device prototype, in vivo device implantation, and in vitro laboratory mechanical testing. First, a patient-specific one-body scaffold implant used for reconstructing a critical-sized defect along the lower border of the sheep mandible ramus was designed using on computed-tomographic (CT) imagery and computer-aided design software. Next, the biomechanical performance of the implant was predicted numerically by simulating physiological load conditions in a digital twin in silico finite element model of the sheep mandible. This allowed for possible redesigning of the implant prior to commencing in vivo experimentation. Then, two types of polymeric biomaterials were used to manufacture the mandibular scaffold implants: poly ether ether ketone (PEEK) and poly ether ketone (PEK) printed with fused deposition modeling (FDM) and selective laser sintering (SLS), respectively. Then, after being implanted for 13 weeks in vivo, the implant and surrounding bone tissue was harvested and microCT scanned to visualize and quantify neo-tissue formation in the porous space of the scaffold. Finally, the implant and local bone tissue was assessed by in vitro laboratory mechanical testing to quantify the osteointegration. The protocol consists of six component procedures: (i) scaffold design and finite element analysis to predict its biomechanical response, (ii) scaffold fabrication with FDM and SLS 3D printing, (iii) surface treatment of the scaffold with plasma immersion ion implantation (PIII) techniques, (iv) ovine mandibular implantation, (v) postoperative sheep recovery, euthanasia, and harvesting of the scaffold and surrounding host bone, microCT scanning, and (vi) in vitro laboratory mechanical tests of the harvested scaffolds. The results of microCT imagery and 3-point mechanical bend testing demonstrate that PIII-SLS-PEK is a promising biomaterial for the manufacturing of scaffold implants to enhance the bone-scaffold contact and bone ingrowth in porous scaffold implants. MicroCT images of the harvested implant and surrounding bone tissue showed encouraging new bone growth at the scaffold-bone interface and inside the porous network of the lattice structure of the SLS-PEK scaffolds.

Nickel nitride-mediated nitric oxide generation for combating implant-associated infections

NiTi alloys are widely used in the fabrication of biomedical implants, and it is essential to endow them with selective antibacterial properties to avoid implant-associated infection. In this study, nickel nitride (Ni3N), as a promising new inorganic nitric oxide (NO) donor, was in situ constructed on the surface of NiTi alloys through a straightforward two-step plasma immersion ion implantation (PIII) strategy. Nickel sites were first exposed by physical bombardment with argon or metal plasma, followed by reaction with nitrogen plasma to form Ni3N. Ni3N can disrupt the transmembrane proton electrochemical gradient by capturing protons to produce ammonia species (NHx), resulting in the accumulation of reactive oxygen species (ROS) as a result of bacterial metabolic disruption. On the other hand, the generated NHx can further react with ROS to produce NO and reactive nitrogen species (RNS). As a result, the Ni3N films exhibited more than 99 % antibacterial efficiency against both gram-negative and gram-positive bacteria. They also demonstrated effective antibacterial properties in a rat subcutaneous implant model. In addition, the modified NiTi alloys exhibit good corrosion resistance and cytocompatibility. This study provides a green, safe, and inexpensive method for constructing metal nitride films on implant surfaces and offers new ideas for the clinical design and fabrication of novel antibacterial implants.

The synergistic effect of body modification and surface coating for the moisture barrier of hydrophilic PU film

Polyurethane (PU) films have established a distinctive position among various protective materials due to their outstanding chemical and physical properties. However, their limited moisture barrier performance hinders their broader applications. To solve this difficult problem, PU film is first modified by adding reactive fillers (MgO) and physical barrier fillers (Modified graphene oxide, M-GO), and then Si-DLC coating is deposited on the surface of the film by hollow cathode plasma immersion ion implantation (HCPIII) method at near room temperature. MgO can react with the water molecules diffused into the film, while the addition of M-GO extends the diffusion path of water molecules. It is revealed that the addition of 5% MgO and 0.5% M-GO, along with the deposition of a 2.56 μm Si-doped DLC coating, leads to a remarkable 14.67-fold reduction in the water vapor transmittance rate (WVTR). The result of molecular dynamics simulations shows that the reactive sheet filler captures the water molecules and reduces the WVTR. In addition, the combination method of PU body modification and surface coating is suitable for polyurethane foam (PUF) to reduce the WVTR as a double coating. It's amazing that the WVTR of PUF significantly reduces by 15.29 times after double-coating. The combination of body modification and surface coating provides an effective route for significantly improving the moisture barrier property of hydrophilic polymer film and polymer foam.

Protecting Orthopaedic Implants from Infection: Antimicrobial Peptide Mel4 Is Non-Toxic to Bone Cells and Reduces Bacterial Colonisation When Bound to Plasma Ion-Implanted 3D-Printed PAEK Polymers.

Even with the best infection control protocols in place, the risk of a hospital-acquired infection of the surface of an implanted device remains significant. A bacterial biofilm can form and has the potential to escape the host immune system and develop resistance to conventional antibiotics, ultimately causing the implant to fail, seriously impacting patient well-being. Here, we demonstrate a 4 log reduction in the infection rate by the common pathogen S. aureus of 3D-printed polyaryl ether ketone (PAEK) polymeric surfaces by covalently binding the antimicrobial peptide Mel4 to the surface using plasma immersion ion implantation (PIII) treatment. The surfaces with added texture created by 3D-printed processes such as fused deposition-modelled polyether ether ketone (PEEK) and selective laser-sintered polyether ketone (PEK) can be equally well protected as conventionally manufactured materials. Unbound Mel4 in solution at relevant concentrations is non-cytotoxic to osteoblastic cell line Saos-2. Mel4 in combination with PIII aids Saos-2 cells to attach to the surface, increasing the adhesion by 88% compared to untreated materials without Mel4. A reduction in mineralisation on the Mel4-containing surfaces relative to surfaces without peptide was found, attributed to the acellular portion of mineral deposition.

3D-printed versatile biliary stents with nanoengineered surface for anti-hyperplasia and antibiofilm formation

Biliary strictures are characterized by the narrowing of the bile duct lumen, usually caused by surgical biliary injury, cancer, inflammation, and scarring from gallstones. Endoscopic stent placement is a well-established method for the management of biliary strictures. However, maintaining optimal mechanical properties of stents and designing surfaces that can prevent stent-induced tissue hyperplasia and biofilm formation are challenges in the fabrication of biodegradable biliary stents (BBSs) for customized treatment. This study proposes a novel approach to fabricating functionalized polymer BBSs with nanoengineered surfaces using 3D printing. The 3D printed stents, fabricated from bioactive silica poly(ε-carprolactone) (PCL) via a sol–gel method, exhibited tunable mechanical properties suitable for supporting the bile duct while ensuring biocompatibility. Furthermore, a nanoengineered surface layer was successfully created on a sirolimus (SRL)-coated functionalized PCL (fPCL) stent using Zn ion sputtering-based plasma immersion ion implantation (S-PIII) treatment to enhance the performance of the stent. The nanoengineered surface of the SRL-coated fPCL stent effectively reduced bacterial responses and remarkably inhibited fibroblast proliferation and initial burst release of SRL in vitro systems. The physicochemical properties and biological behaviors, including in vitro biocompatibility and in vivo therapeutic efficacy in the rabbit bile duct, of the Zn-SRL@fPCL stent demonstrated its potential as a versatile platform for clinical applications in bile duct tissue engineering.

Controlling plasma-based surface modifications of an austenitic alloy by thermochemical and athermal diffusions

Under nitrogen plasma immersion ion implantation, the energy density per pulse EPulse/A was found to be proportional to the amount of the N-expanded austenite phase (γN) in a superaustenitic stainless steel, as previously seen for an austenitic-ferritic alloy. Since γN occurs in a range of stoichiometries, the parameter was also contrasted with the ion fluence Γ, which affects the retained dose. Γ varies inversely with EPulse/A and influences oppositely the properties of the modified surfaces. The temperature was the same among the treatments (320 °C) to rule out thermal diffusion as an extra variable. The increase of EPulse/A (for applied voltages 6.2–10.4 kV) produces thicker layers (1.4–2.2 µm), as an increase in lattice defects and stresses enhances N-diffusion, while high Γ values favor the N-saturation at the top surface for the opposite reason. The lowest Epulse/A (6.2–9.5 kV) result in brittle cases with a possible thin nitrides layer on top, whereas γN prevails in the ductile layer produced by the highest one (10.4 kV). The N-concentration governs the strength against plastic deformation: hardness varies up to 32% from the highest (6.2 kV) to the lowest Γ treatment (10.4 kV). In summary, the correlation of Epulse/A with Γ is indispensable for controlling properties of the modified surfaces for performance purposes.

Effect of Dose Rate on Tribological Properties of 8Cr4Mo4V Subjected to Plasma Immersion Ion Implantation

The lack of service lifetime of bearings has become a bottleneck that restricts the performance of aero engines. How to solve or improve this problem is the focus of most surface engineering researchers at present. In this study, plasma immersion ion implantation was conducted; in order to enhance the ion implantation efficiency and improve the wear resistance of 8Cr4Mo4V bearing steel, the dose-rate-enhanced method was adopted during ion implantation. The surface roughness, phase constituents, elemental concentration, hardness, contact angle and wear resistance of samples after ion implantation was determined by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD), elemental dispersive spectroscopy (EDS), X-ray diffraction, nanoindentation tester, universal friction and wear tester, etc. The results showed that the high-dose-rate method had a significant enhancement influence on ion implantation efficiency. At the dose rate of 2.60 × 1017 ions/cm2·h, the roughness of Ra decreases from 24.8 nm to 10.4 nm, which is decreased by 58.1% for the dose rate of 7.85 × 1017 ions/cm2·h. XRD confirmed that the implanted samples consisted of the Fe(M) and Fe2–3N phase and CrN which depends on the implantation dose rate. Meanwhile, the surface hardness was improved from 11.1 GPa to 16.9 GPa and enlarged the hardened region; more valuably, the surface state of samples via high-dose-rate implantation exhibits hydrophobicity with high roughness which is able to store debris and decrease the abrasive wear during testing; thereby, the wear resistance was greatly enhanced by high-dose-rate plasma immersion ion implantation.

The effect of efficient high-dose-rate plasma immersion ion implantation on microstructure and properties of 8Cr4Mo4V steel

8Cr4Mo4V steel was implanted with 20 keV nitrogen ions dose rates with fluences between 2.60 × 1017 ions/cm2·h and 1.04 × 1018 ions/cm2·h. The samples were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), elemental dispersive spectroscopy (EDS), secondary ion mass spectroscopy (SIMS), auger electron spectroscopy (AES) and nanoindentation test. The stopping and range of ions in matter (SRIM) code was used to calculate vacancies and displacements distributions. The results reveal that the implanted surface layer contains the phase composition of Fe(M) and Fe2–3N. The peaks of the samples with a dose rate from 2.60 × 1017 to 7.85 × 1017 ions/cm2·h are broadened and slightly shift to left by 0.777° towards comparing to the dose rate of 1.04 × 1018 ions/cm2·h. A significant improvement in roughness of Ra (∼10.4 nm) is attained for the dose rate of 7.85 × 1017 ions/cm2·h. The lattice parameters of the smallest grain size, the highest micro-strain and dislocation density of 11.78 nm, 7.716 × 10−3 and 1.559 × 1016 /m2 respectively were obtained for the dose rate of 5.18 × 1017 ions/cm2·h. There exists a deep diffusion zone of about 400 nm for the dose rate of 7.85 × 1017 ions/cm2·h and 1.04 × 1018 ions/cm2·h, which is 4 times deeper than other implanted samples. Furthermore, the nanohardness of implanted samples improved notably as well, especially at the dose rate of 8.64 × 1017 ions/cm2·h, reaches to a higher value of 16.3 GPa, which is 46.8 % higher than that of non-implanted sample of 11.1 GPa, implies that the properties of samples strongly affected by the implantation dose rate.

Ti-Al-C Based MAX Phase Coating As Corrosion Protection for Ferritic Bipolar Plates

Metallic bipolar plates in fuel cells have the advantages of high electrical conductivity, low permeability to the reactants and gases, and easy manufacturability. However, resistance to corrosion under long term operation conditions limits their practical use in the fuel cell. Owing to the importance of corrosion stability, materials such as austenitic stainless steels, Ni-based alloys and coated titanium or stainless steel plates are currently being used in bipolar plates, although ferritic steels would be cost effective. A pinhole-free anticorrosion coating can help in application of the ferritic steels in fuel cells. MAX phase materials offer excellent corrosion stability and high electronic conductivity and have been successfully tested for corrosion protection of metallic bipolar plates. In the current work, Ti-Al-C-based MAX phase coatings were prepared using high power impulse magnetron sputtering (HiPIMS). The HiPIMS process was in some cases also combined with plasma immersion ion implantation (PIII) to study the influence of the high energetic ion implantation process on the structure and performance of the resulting MAX phase layer. The deposited samples were annealed at 800 °C for 2 h in Ar atmosphere. The structure and composition of the coatings produced were studied with X-ray photoelectron spectroscopy, atom probe tomography and transmission electron microscopy. The corrosion performance of the layers was studied using a scanning flow cell coupled with inductively coupled plasma mass spectroscopy.

Modelling the development of biological structures displaying longitudinal geometries in vitro: culturing pluripotent stem cells on plasma-treated, growth factor-coupled polycaprolactone fibres

Many biological structures such as nerves, blood and lymphatic vessels, and muscle fibres exhibit longitudinal geometries with distinct cell types extending along both the length and width of internal linear axes. Modelling these three-dimensional structures in vitro is challenging: the best-defined stem-cell differentiation systems are monolayer cultures or organoids using pluripotent stem cells. Pluripotent stem cells can differentiate into functionally mature cells depending on the signals received, holding great promise for regenerative medicine. However, the integration of in vitro differentiated cell types into diseased tissue remains a challenge. Engineered scaffolds can bridge this gap if the appropriate signalling systems are incorporated into the scaffold. Here, we have taken a biomimicry approach to generate longitudinal structures in vitro. In this approach, mouse embryonic stem cells are directed to differentiate to specific cell types on the surface of polycaprolactone (PCL) fibres treated by plasma-immersion ion implantation and to which with lineage-specifying molecules have been covalently immobilised. We demonstrate the simplicity and utility of our method for efficiently generating high yields of the following cell types from these pluripotent stem cells: neurons, vascular endothelial cells, osteoclasts, adipocytes, and cells of the erythroid, myeloid, and lymphoid lineages. Strategically arranged plasma-treated scaffolds with differentiated cell types could ultimately serve as a means for the repair or treatment of diseased or damaged tissue.

INFLUENCE OF DOPING WITH CARBON AND NITROGEN ON THE PHOTOACTIVITY OF TiO2 THIN FILMS OBTAINED WITH MePIIID

Titanium dioxide is well known as a photoactive material activated under ultraviolet irradiation. It is either employed as a photocatalyst or it exhibits superhydrophilic behavior after obtaining reduced surface energy under illumination used for self-cleaning or anti-fogging surfaces. For increasing the reactivity of thin films under solar illumination, a reduced band gap is desired. Doping with transition metals or nitrogen has been reported in the literature. However, the incorporation of nitrogen into a growing film is a much more complex process that is presently not completely understood. TiO2 thin layers were produced by metal plasma immersion ion implantation and deposition at room temperature at a pulse voltage of 0–5 kV and a duty cycle of 9 % for an apparently amorphous layer. An auxiliary rf plasma source was employed to increase the growth rate at low gas flow ratios. By adjusting the geometry between the incident ion beam, sputter target and substrate independently of the primary ion energy and species, a controlled deposition of samples was possible. Conventional ion implantation was employed to implant either carbon or nitrogen ions below the surface for bandgap engineering. The resulting thin films were subsequently investigated for optical properties, stoichiometry, structural properties, surface topography and photoactivity.