Design Tool Research Articles

Exploring the Use of Alternative Promoters for Enhanced Transgene and sgRNA Expression in Atlantic Salmon Cells.

This study facilitates design of expression vectors and lentivirus tools for gene editing of Atlantic salmon. We have characterized widely used heterologous promoters and novel endogenous promoters in Atlantic salmon cells. We used qPCR to evaluate the activity of several U6 promoters for sgRNA expression, including human U6 (hU6), tilapia U6 (tU6), mouse U6 (mU6), zebrafish U6 (zU6), Atlantic salmon U6 (sU6), medaka U6 (medU6), and fugu U6 (fU6) promoters. We also evaluated several polymerase type II (pol II) promoters by luciferase assay. Our results showed that hU6 and tU6 promoters were the most active among all the tested U6 promoters, and heterologous promoters (CMV, hEF1α core) had higher activity compared to endogenous Atlantic salmon promoters sHSP8, sNUC3L, sEF1α. Among endogenous pol II promoters, sEF1α and sHSP8 displayed higher activity than sNUC3L, sHSP703, sHSP7C, sXRCC1L, and sETF. We observed that extending the promoter sequence to include the region up to the start codon (ATG) resulted in a significant increase in expression efficiency for sNUC3L and sEF1α. We also show that mutating the PRDM1 motif will significantly decrease the activity of the sEF1α promoter. The presence of the PRDM1 motif in sHSP8 promoter was also associated with relatively high expression compared to the promoters that naturally lacked this motif, such as sNUC3L. We speculate that this short sequence might be included in other promoters to further enhance the promoter activity, but further experiments are needed to confirm this. Our findings provide valuable insights into the activity of different promoters in Atlantic salmon cells and can be used to facilitate further transgenic studies and improve the efficiency of transgene expression in Atlantic salmon.

Sensor-based isometric contraction examination tool after ankle sprain injury and ankle instability

Background. Previous studies have examined the application and benefits of sensors, both in sports and health. Unfortunately, the design of sensor-based isometric contraction examination tools after ankle sprain injuries and ankle instability is still rarely carried out. Purpose. The aim of this research is to design a sensor-based isometric contraction examination tool after ankle sprain injury and ankle instability. Material and Methods. The design used is research and development involving experts, namely instrumentation physics, sports physiology, and physiotherapy to assess the suitability of the tool before field trials. The tool developed is the “Isometric Contractions Test”, which is designed in the form of a box with dimensions of 10 cm (height) x 10 cm (width) x 25 cm (length). Various electronic components are also used, such as Arduino Pro Mini, Flexi Sensors, switch buttons, and OLED LCD as digital reading output. A total of 10 participants aged 18-23 years participated voluntarily for the field trial. Participants were men and women who had experienced sub-acute or chronic ankle sprains and ankle instability. The data obtained were analyzed using the correlation method. Result. The results of this study report that this sensor-based isometric contraction examination tool is valid, reliable, effective, and practical in detecting and treating post-injury healing of ankle sprains and ankle instability. Conclusions. This tool can be used to assist physiotherapists in carrying out observations and evaluations to treat healing quickly and precisely, both in athletes and non-athletes.

The Impact of the Radius of the Cutting Blade during the Processing of C 60 ± 2 HRC (DIN) Steel

This study investigates the thermal dynamics of the turning process for C60 steel, focusing on the influence of various machining parameters on temperature rise. Integrating experimental methods and statistical analysis, the research examines the effects of cutting speed (v), feed rate (f), depth of cut (a), and cutting insert tip radius (r) on the average temperature in the cutting zone. Experiments were conducted on heat-treated C60 steel rings, using a custom fixture and a modified Kennametal insert holder to ensure precise temperature measurements, collected via a natural thermocouple method. The findings reveal that cutting speed is the most significant factor influencing temperature rise, followed by feed rate, while depth of cut has a minor impact. Notably, the radius of the cutting insert tip is inversely proportional to the temperature, with an increase in the tip radius resulting in a decrease in average temperature. This inverse relationship underscores the potential for optimizing tool design to enhance heat dissipation and reduce thermal stress on the cutting tool. A fourth-degree polynomial model was developed through regression analysis to correlate thermovoltage (V) with temperature (T), providing a quantitative framework for predicting thermal behavior. The model highlights that cutting speed has the greatest effect on temperature rise, with the highest recorded temperature being 795.09°C. Conversely, larger radius of the cutting insert tip corresponds to lower average temperatures, stabilizing around 757.22°C. These insights offer actionable strategies for optimizing machining processes. By strategically adjusting cutting parameters, particularly cutting speed and feed rate, manufacturers can achieve significant improvements in tool life and product quality. The developed mathematical model serves as a predictive tool for fine-tuning machining conditions, ensuring a balance between productivity and tool longevity. This research contributes substantially to the understanding of thermal dynamics in machining processes. It provides a comprehensive analysis and robust modeling of the effects of cutting parameters on temperature rise, supported by rigorous experimental data and statistical validation. The study underscores the importance of considering thermal effects in machining to optimize efficiency, tool life, and product quality, offering valuable insights for both academic research and practical applications in the field of machining and process optimization.

Feasibility of Robotic Transorbital Surgery.

The transorbital approach (TOA) facilitates access to pathologies lateral to the optic nerve, a region that is difficult to access with an endonasal approach. In this study, we sought to investigate the feasibility of robotic-assisted surgery in lateral TOA. Six colored-silicon-injected human postmortem heads were prepared for dissection. The DaVinci Xi model was used with a 0-degree camera, 8 mm in diameter. A black diamond microforceps with an 8-mm diameter and 10-mm jaw length was used. The entry point of V1 (superior orbital fissure), V3 (foramen ovale), and posterior root of the trigeminal ganglion were chosen as the surgical targets. The length from the entry opening to each target point was measured. The angles formed between pairs of target points were measured to obtain the horizontal angle (root of the trigeminal ganglion-entry-V1) and the vertical angle (root of the trigeminal ganglion-entry-V3). Dissection was performed on 12 sides (6 specimens). The median distance from the entry point was 55 mm (range 50-58 mm) to the entry point of V1 (superior orbital fissure), 65 mm (range 57-70 mm) to the entry point of V3 (foramen ovale), and 76 mm (range 70-87 mm) to the root of the trigeminal ganglion. Meanwhile, the median of surgical angle between the entry point and the target was 19.1° (range 11.8-30.4°) on the horizontal angle and 16.5° (range 6.2-21.6°) on the vertical angle. This study found that application of lateral TOA in robotic-assisted surgery is premature because of the large size of the tool. However, although the entrance in lateral TOA is narrow, the internal surgical space is wide; this offers potential for design of appropriate surgical tools to allow increase tool usage.

Enhancing User Experience in Small Academic Libraries: Leveraging Matomo Analytics as a UX Design Tool.

Enhancing User Experience in Small Academic Libraries: Leveraging Matomo Analytics as a UX Design Tool.

SCADA Implementation on Solar Panel Electricity Consumption Monitoring and Regulation System

In an effort to motivate students and understand application of SCADA to the Solar Panel system which is one source potential non - fossil energy to be used as solution to meeting sustainable energy needs.​ Where in its operation , efficiency and reliability Solar Panel system is still a major problemthat must be overcome . Utilization of Supervisory Control and Data Acquisition (SCADA) in management Solar Panel Systems (PLTS) have become significant solution​ to improve loading efficiency . The purpose of this research is to create a prototypes solar panel practicum as a learning media to motivate student in understanding how solar panels work and can apply the process of monitoring and regulating solar panel system with SCADA in real-time. The equipment used​ includes Solar Panels, Solar Charger Controller (SCC), Inverter, Battery , PLC Omron CP1E-NA20DR-A and CP1W AD041, ACS712 Current Sensor , ZMPT101B Voltage Sensor, DHT22 Temperature and Humidity Sensor and Light Sensor (LDR) as well as CX- Programmer software Ver. 9.5 and CX -Supervidor Ver.4.0. The method used is Research and Development method as the basic for design and manufacture of solar panel practicum tools and the application of SCADA to the monitoring system and electricity usage of solar panels . From the results of tests conducted with the application of SCADA on solar panels can monitor Voltage , Current , Power, Temperature , Light and load usage regulator electric solar panels based on electrical energy consumption, as well as the condition of electrical equipment connected to the solar panel system with an average error values : Voltage 0.084%, Current 0.155%, Power 0.107% and Temperature 45 0C and Light 658.7 Lux.

An Elderly-Oriented Form Design of Low-Speed New Energy Vehicles Based on Rough Set Theory and Support Vector Regression

With the current trend of social aging, the travel needs of the elderly are increasingly prominent. As a means of urban transportation, low-speed new energy vehicles (NEVs) are widely used among the elderly. Many studies are devoted to exploring the function of cars and the travel modes that meet the needs of older people. However, in addition to product performance, the Kansei needs of users also play a key role in communication between enterprises and users. Therefore, the problem of how to improve car shapes in the initial stage of design to meet the Kansei needs of elderly users remains to be solved. In order to fill this gap, the design of low-speed NEVs are selected as the study objects so as to explore the relationship between the visual perception of elderly users and car design; thus, a design method for the form of elderly-oriented cars is proposed. Firstly, using the research framework of Kansei engineering, factor analysis is used to cluster elderly-oriented Kansei factors. Second, the cars’ appearances are deconstructed by morphological analysis, and the key design features affecting elderly-oriented satisfaction are identified by a rough set attribute reduction algorithm. Finally, support vector regression is used to establish a mapping model of elderly-oriented Kansei factors and the key design features to predict the elderly-oriented form design of optimal low-speed NEVs. The research results show that selecting “Hub6”, “Headlight9”, “Car side view2”, “Rearview mirror9”, and “Front door10” in the form deconstruction table for low-speed NEVs can elicit optimal emotions in elderly users. The research results enable enterprises to more effectively understand the emotional cognition of elderly users related to the form of low-speed NEVs and improve the purchase desire and satisfaction of elderly users, providing references and guidance for the elderly-oriented design and development of intelligent transportation tools.

Designing and validating a clinical decision support algorithm for diabetic nephroprotection in older patients

BackgroundOlder patients with diabetic kidney disease (DKD) often do not receive optimal pharmacological treatment. Current clinical practice guidelines (CPGs) do not incorporate the concept of personalised care. Clinical decision support...

Interactive CAD Layout of Reflection-Based Mirror Metrology Systems

Concentrating solar mirrors need to accurately focus sunlight onto a receiver. Since mirror surface normal determines reflected light direction, reflection-based metrology methods that measure surface normal have the advantage of directly measuring the mirror’s intended functional performance characteristic. Several methods have been reported that produce high-resolution measurements of mirror surface normal of concentrating solar mirrors [1-8]; these systems typically employ an optical target, a camera, and sometimes an external light source. These elements must be placed in a configuration that satisfies multiple feasibility constraints, including mechanical and optical visibility and reflection constraints. For complex problems or installations in cluttered environments, it can be difficult to analyze all of these constraints manually. We have created a computer automated design (CAD) tool that aids in visualization of reflection-based metrology systems, making it possible to determine layouts for complex metrology design problems. The tool is implemented SolidWorks, a commercial CAD system [9]. By exploiting the SoidWorks constraint satisfaction mechanism, the tool is able to present interactive visualization of reflection and field of view constraints in real time without any additional code or macros. The tool supports ease of use and multiple design configurations through an ordinary spreadsheet interface. The tool can be used to address a variety of reflection-based metrology design problems, and is available to the public as open source.

GraphiQ: Quantum circuit design for photonic graph states

GraphiQ is a versatile open-source framework for designing photonic graph state generation schemes, with a particular emphasis on photon-emitter hybrid circuits. Built in Python, GraphiQ consists of a suite of design tools, including multiple simulation backends and optimization methods. The library supports scheme optimization in the presence of circuit imperfections, as well as user-defined optimization goals. Our framework thus represents a valuable tool for the development of practical schemes adhering to experimentally-relevant constraints. As graph states are a key resource for measurement-based quantum computing, all-photonic quantum repeaters, and robust quantum metrology, among others, we envision GraphiQ's broad impact for advancing quantum technologies.

Design and utilization of a decision support tool to advance energy efficiency in industries

The industrial sector contributes significant environmental impact due to greenhouse gas (GHG) emissions. It is necessary to investigate the energy flow from resources, and the possibilities for lowering energy use through energy management. Energy modeling and visualization have been identified as effective and powerful methods for investigating energy-saving potential and improving energy efficiency. In this study, the Sankey diagram-based decision support tool is designed and developed to illustrate the energy flow and the potential for energy savings from various processes in different industrial sectors. The tool is developed in Python and presented as a web-based dashboard, making it accessible to various users. The web-based Sankey diagram tool allows the user to comprehend the present state of energy consumption, costs, and CO2 emissions, as well as the potential for enhancing system flexibility and efficiency in the industry. The opportunities for heat recovery, renewable energy sources, and energy storage technologies are discussed as an assumed case study in 4 specific scenarios. Finally, the findings validate the significance of energy-efficient solutions in industry utilizing the proposed tool. This underscores the importance of adopting sustainable practices within industries, ultimately contributing to the enhancement of the sector's overall sustainability and resilience.

OpenECAD: An efficient visual language model for editable 3D-CAD design

Computer-aided design (CAD) tools are utilized in the manufacturing industry for modeling everything from cups to spacecraft. These programs are complex to use and typically require years of training and experience to master. Structured and well-constrained 2D sketches and 3D constructions are crucial components of CAD modeling. A well-executed CAD model can be seamlessly integrated into the manufacturing process, thereby enhancing production efficiency. Deep generative models of 3D shapes and 3D object reconstruction models have garnered significant research interest. However, most of these models produce discrete forms of 3D objects that are not editable. Moreover, the few models based on CAD operations often have substantial input restrictions. In this work, we fine-tuned pre-trained models to create OpenECAD models (0.55B, 0.89B, 2.4B and 3.1B), leveraging the visual, logical, coding, and general capabilities of visual language models. OpenECAD models can process images of 3D designs as input and generate highly structured 2D sketches and 3D construction commands, ensuring that the designs are editable. These outputs can be directly used with existing CAD tools’ APIs to generate project files. To train our network, we created a series of OpenECAD datasets. These datasets are derived from existing public CAD datasets, adjusted and augmented to meet the specific requirements of vision language model (VLM) training. Additionally, we have introduced an approach that utilizes dependency relationships to define and generate sketches, further enriching the content and functionality of the datasets.

Accounting for plume rise of aircraft emissions and shoreline meteorology enhances AERMOD’s description of concentrations measured around Los Angeles airport

ABSTRACT The Aviation Environmental Design Tool (AEDT), developed by the FAA, is used to analyze the environmental impact of airport activities on air quality and noise near airports. AEDT incorporates AERMOD to estimate concentrations resulting from aircraft emissions, which possess horizontal momentum as well as buoyancy. The current version (v23132) of AERMOD incorporates plume dynamics associated with such emissions as an ALPHA option, which is described in Pandey et al. (2023). AERMET, AERMOD’s meteorological processor does not account for the meteorology of the land-water interface that is likely to be important for airports located on the shorelines of lakes or oceans. An approach to include these effects in AERMOD is described in Pandey et al. (2022). This study examines the impact of including plume rise and shoreline effects in AERMOD by evaluating model estimates of NOX and SO2 with corresponding measurements made during the Los Angeles Airport Air Quality Source Apportionment Study (AQSAS) in the winter and summer of 2012. The performance statistics resulting from this model evaluation suggest that the inclusion of plume rise of aircraft emissions, and shoreline effects on meteorological inputs is likely to improve AERMOD’s ability to estimate the impact of airport emissions on surrounding air quality. Implications: Because airport emissions, particularly those from aircraft, affect local air quality, the National Environmental Policy Act (NEPA) requires the use of dispersion models such as AERMOD to assess compliance of air quality regulations when potential expansions of airport activity are planned. The current regulatory version of AERMOD does not include aircraft-specific plume rise and shoreline-related meteorological processes, which affect the dispersion of airport emissions. The preliminary evidences presented in Pandey et al. (2022; 2023) suggest that the incorporation of these effects will enhance AERMOD’s ability to estimate NOX and SO2 concentrations associated with airport emissions. These enhancements are beneficial not only for policy-making and regulatory compliance but also for promoting sustainable development near airports and protecting public health.

Comparison of design education documents and the disconnect between designer priorities, tools, and occupant assumptions

While low-level physiological human-factor design strategies have long been discussed in the literature, these design methods are infrequently seen in architecture education and licensure requirements – leaving designers to think about future occupants on their own. In this paper, we study underlying causes of perceptions–and misperceptions–as to the role human factors play in the design process. We present findings from a large-scale textual analysis supported by two studies: (1) building users assume a higher integration of human factors in design tools than how designers perceive the integration and (2) designers place higher importance on less tangible design concepts than building users. Our findings suggest design tools that can augment the knowledge of designers with respect to human physiology and crowd simulations are pertinent to current workflows. We also infer there are likely additional important-to-explore disconnections between users and designers.

Sketch, CAD, or simulate the build? Exploring novice designers’ design representation use in design for additive manufacturing

ABSTRACT The growing adoption of digital tools to support additive manufacturing (AM) calls for designers to rethink their use of design representations in the design process. For example, designers can automate concept generation through generative design, reducing reliance on conceptual sketches. Little research has explored designers’ use of design representations in design for AM (DfAM). We explored this gap through an observational study with novice designers involving an open-ended DfAM task, and their use of design representations was captured using eye-tracking. Overall, participants spent a significant amount of time CAD modeling their designs compared to using other design representations such as sketches and build simulations. Moreover, participants’ design representation usage did not relate to the creativity of their designs. However, participants who generate high-performing designs spent more time CAD modeling and less time sketching – a novel and important finding from our study. Therefore, the advancement of digital design tools and the growing adoption of digital manufacturing processes may result in designers conceptualizing their solutions in embodiment-based tools such as CAD and relying less on low-fidelity tools such as sketching. Our results provide an essential first step toward creating a generalized framework for designers to employ different design representations in DfAM.

Developing complex thinking through a systemic framework for water education: a case study on the domestic water cycle in French curricula

This study explores systemic approaches in water education, focusing on the Domestic Water Cycle (DWC) as a complex educational topic. Water education aims to cultivate responsibility for water resources, engage individuals in water-related issues, and promote sustainable behaviours. Understanding water’s complexity is paramount, and systemic approaches offer a promising way to enhance this understanding. This research develops a comprehensive systemic tool for curriculum designers, educators and teachers to implement water education projects effectively. It also analyses the representation of DWC in official documents related to compulsory education in France, focusing on cycles 1–4. Using qualitative content analysis, the study examines these documents in depth. A four-step methodology was developed to create a systemic diagram of the DWC, incorporating various approaches as guiding principles. This diagram was then used to analyze educational programs. Findings reveal progressive development in DWC treatment across educational levels. Cycles 1 and 2 include some DWC elements, but the overall flow is not identified. In Cycle 3, several elements and relationships are not explicitly included. However, Cycle 4 exhibits a stronger systemic approach, addressing DWC complexity. This study demonstrates that integrating a systemic approach and utilizing a systemic tool can provide valuable support in teaching complexity effectively. Furthermore, it suggests this approach can help students develop essential skills such as problem-solving, understanding interrelationships, and making informed decisions across various domains, including environmental studies.

Phase change material properties identification for the design of efficient thermal management system for cylindrical Lithium-ion battery module

Performance and life of Lithium-ion battery packs in EVs and energy storage applications are limited by the thermal profile of cells during its life. Passive cooling technique based on Phase Change Material (PCM) is employed for mitigating thermal issues associated with Lithium-ion cells. The challenge with PCM materials is the trade-off between its latent heat of fusion, thermal conductivity and specific heat. Detailed CFD analysis is carried out to study the impact of PCM thermal properties on battery pack thermal profile and provide guidelines for PCM properties selection and usage of existing PCM materials. Impact of critical PCM properties such as latent heat (100–250 kJkg−1), thermal conductivity (0.2–23 Wm−1K−1), melting temperature and thickness of PCM material on thermal performance of a battery module during rapid discharge rate of 25 A (3.2C) is investigated. Battery module maximum temperature (Tmax) reaches 54°C and temperature difference (∆T) to 5.5°C while operating at 35°C with 124 kJkg−1and 0.2 Wm−1K−1. It is found that, PCM with higher latent heat (≥ 175 kJkg−1), thermal conductivity (≥ 3 Wm−1K−1), PCM thickness (≥ 3 mm) and appropriate phase change temperature 41-44°C exhibit improved heat dissipation for high discharge rates by effectively reducing the Tmax to 44.4°C and ∆T to 2.4°C (25 A and 35°C ambient). Further, ways to mitigate low latent heat capacity and thermal conductivity of PCM through increasing PCM material usage (i.e. inter cell distance) is emphasized. Results of the present study can be considered as a design tool for PCM development engineers which could be cost effective both in-terms of development time and effort.

FEA-based pole arc optimization and sensitivity analysis of 8/6 SRM for EV application

The optimization of the pole arcs and sensitivity analysis of a 4-phase 8/6 Switched Reluctance Motor (SRM) using the Finite Element Analysis (FEA) technique for the Electric Vehicle (EV) application is presented in this article. The motor's power rating is estimated from the tractive force of an e-rickshaw(3-wheeler). Optimizing the pole arc in SRMs is essential for obtaining an optimal balance of performance, efficiency, and operating smoothness. This makes it a vital part of SRM design. The motor performance is analyzed by fixing the stator pole arc while varying the rotor pole arc and vice versa. The main performance attributes like torque, torque ripple, torque per rotor volume, and efficiency of an 8/6 SRM with various pole arc values are examined using the transient FEA method. A sensitivity analysis is conducted to evaluate the range of variation in the performance parameters of the motor when the pole arcs vary. Various performance indices, such as torque, torque ripple (TR), efficiency, and Torque Per Volume (TPV), are considered for the analysis. The sensitivity analysis is carried out based on the transient analysis. Finally, based on the findings, the optimal combination of pole arcs is determined and analyzed the performance using the FEA method. An electromagnetic design tool called Infolytica MOTORSOLVE is used to construct the FEA models and extract the characteristics.

(Invited) Advanced III-V-on-Si Heterogeneously Integrated Platforms for Next Generation Silicon Photonics Integrated Circuits

The field of Silicon Photonics has experienced a solid and continuous progress over the last few years, gaining in technological maturity, design tools, and new methods [1]. The deployment of low-cost, compact, and power-efficient photonic circuits with a high wafer yield and robustness stands as one of the fundamental pillars that sustain such progress [2]. Presently, photonic circuit technology has diversified its number of available platforms. Despite the fact that indium phosphide (InP) [3] and silicon-on-insulator (SOI) platforms are still considered as the workhorses of integrated photonics in terms of maturity and deployment of active (InP) and passive (SOI) components, other alternatives such as germanium-on-silicon [4], silicon nitride-on-insulator [2] or hybrid solutions combining different functional materials with Si are gaining momentum [5]. A representative example is the heterogeneous III-V/Si platform [6], which has been used to develop compact photonic circuits with on-chip gain. Contrarily to the hybrid integration, the III-V-on-Si heterogeneous integration avoids the constraints of chip-to-chip alignment while enabling the simultaneous integration of hundreds of III-V gain chips in a scalable fashion. Still, the integration methods of such III-V materials on silicon need to be improved to attain the maturity level of the monolithic III-V platform, which benefits from a complete palette of technological solutions not yet available in the III-V-on-Si heterogeneous integration. More recently, an advanced heterogeneous scheme based on wafer-seed-bonding and epitaxial regrowth has emerged [7]–[9]. The ambition is to create a generic integration scheme combining the best offered by the III-V and the Si-photonics platforms. The regrowth capability gives access to the large epitaxial toolkit available in the conventional InP monolithic platform, where several epitaxial steps are often implemented [10][11]. To cite some of them, the epitaxial regrowth of III-V materials to bury III-V lasers bonded onto silicon are object of intense research nowadays to overcome the thermally inefficient buried oxide [12].In this paper, we will review the advances on III-V-on-Si heterogeneous integration through the implementation of several key demonstrators and building blocks for silicon photonics, including on-chip semiconductor optical amplifiers, lasers and electro-absorption modulators. We will discuss the progress and benefits of the direct seed bonding and regrowth as well as new device designs to improve the performance.

On the Use of Pad Mechanical Properties as a Proxy for Conditioning Response

A proliferation of pad materials in recent years, coupled with the increasing complexity of process integration and limited resources available for process development, has highlighted the need for a more in depth understanding of conditioning interactions and better predictive tools for process and consumable design. We have previously noted a range of conditioning response as illustrated in Figure 1. As the figure illustrates, on some materials the surface height distribution imparted by the pad conditioner is shifted to the left relative to the exponential signature of the pad native porosity which is used as a reference. Denoted regime 1, these surfaces are characterized by the prevalence of “eyelid” features which obscure the line-of-sight path to the bottoms of the pores. In regime 2, the surface height distribution is more balanced, with a smooth transition between the exponential porosity signature and the conditioning signature. In regime 3, there is an abrupt disconnect between the exponential porosity signature and the conditioner signature. Such surfaces are characterized by deep gouges.We are investigating pad material tensile properties as a proxy to help understand and predict these conditioning responses. Figure 2 illustrates the range of typical tensile behavior for polymers. While Figure 2 invokes temperature as the variable that drives these behaviors, note that strain rate can also drive tensile behavior across this range with high temperature being analogous to low strain rate and vice versa.Figure 3 and Table 1 summarize some results from our testing of IC1000, VP5000, VP6000, IK4250H and IK4350L. We have determined that grooved pad materials at their nominal dimensions are adequate for testing according to ASTM D638: Standard Test Method for Tensile Properties of Plastics. Typical delivered pad thickness is within the specifications for sample thickness, and as long as the grooves are oriented to be substantially parallel with the strain axis (pulling direction) reproducible results can be obtained. A range of properties spanning at least about 2x is observed in these pads.Figure 4 gives one example of how this information can be directly applied. The figure illustrates a manifestation of the threshold behavior that is typically observed when conditioning with a pad conditioner with uniform tip height, where all the cutting points are controlled within a height range of about 10 µm. As opposed to a conventional conditioning platform, where there is a much wider range of tip heights, the uniform height-controlled conditioner exhibits a threshold behavior where no measurable cutting occurs below a limiting condition down-force (cdf). Figure 4 illustrates the disconnect between a high down-force, accelerated cutting test, using 14 lbs cdf and designed to return the “CR” value for a conditioner, and typical process cdf levels, in the range of 5 lbs cdf. Note that CR values are generally about an order of magnitude higher than comparable polishing tool level pad wear rates. Whereas conventional platforms yield a linear response between CR and tool level pad wear rates, the uniform height design exhibits an offset, such that at low CR levels, low pad wear rates are observed. The position of this threshold is a function of pad type. These data suggest that this threshold can be correlated with the mechanical strength of the pad material, as determined by the tensile test results.We have also explored the effect of strain rate on tensile response. Strain rates in a typical CMP process may be as high as 105 s-1, and as shown in Figure 2, strain rate can have a significant effect on material behavior. Figure 5 illustrates typical results, illustrating the extremes of response for this group of pads, and Figure 6 shows the normalized response of offset yield and tensile strength as a function of strain rate. Of these materials, only IK4350L exhibits a divergent response, and as shown in Figure 7, IK4350L typically exhibits the most abrupt transition between the exponential porosity signature and the conditioner cutting signature, indicating a tendency towards the gross over-conditioning behavior characteristic of regime 3.Over the range of strain rates explored here, all of these materials can be characterized as “rubbery”. This rubbery behavior can be understood in the context of reported property measurements of CMP pads, which indicate distinct glass transitions related to the soft and hard phases of the polyurethane from which the pad is made. This analysis suggests that pad behavior is dominated by the “rubbery plateau” of the soft segment of the polymer, with the glass transition of the hard segment occurring above typical polishing temperatures. Figure 1