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Lambda News

Lambda is a leading supplier of characterisation, measurement and analysis equipment, applied to signals from DC to Light. Our company provides hardware, software and integrated solutions throughout the UK & Ireland.

  • Absolute Position Measurement: Multiwavelength-interferometry-based sensor redefines precision position metrology

    An absolute position measurement system has a noise floor of less than 0.02 nm/√Hz over a range of 1.2 mm.

    Measuring to the nanometer scale is no small feat—getting there takes careful engineering and a fundamentally good sensor. The sensors used for stage position feedback inside semiconductor lithography tools regularly achieve this level of precision. Zygo has supplied displacement measuring interferometers (DMIs) to satisfy this application for 30 years.

    Zygo has recently introduced the ZPS, an optical sensor system that delivers absolute position with subnanometer precision. Many sensors in the market claim to have this capacity—without an industry-standard definition, though, it is difficult to compare two different sensors and know what performance to expect. This article shares our experience, clarifies the common terms that describe the quality of a position sensor, and shows how ZPS delivers good performance.1

    The ZPS system is a fiber-based optical sensor system that provides absolute position with low noise (≤0.02 nm/√Hz) and high repeatability (0.5 nm 3σ) over a 1.2 mm travel range. The system supports up to 64 synchronised channels with user-selectable data rates up to 208 kHz. It has utility in applications that require a high quality of measurement, a large number (>16) of measurement channels, or both.

    Optical sensors provide several advantages over other technologies like capacitance gauges or encoders. Optical sensors are capable of direct measurements, insensitive to electromagnetic interference, and generate no heat. Cabling restrictions are minimal, as fiber cables can be quite long and are more flexible than electrical cables. ZPS sensors are very compact (3 × 27 mm on average) and enable metrology in applications with severe space constraints.

    How ZPS works

    ZPS combines three kinds of interferometry in a single device: multiwavelength, heterodyne, and coupled-cavity interferometry (see Fig. 1).


    FIGURE 1. The chassis (a) and sensor (b) are shown for a ZPS absolute-position sensor; the sensor is based on multiwavelength (c), heterodyne, and coupled-cavity interferometry (d).

    Multiwavelength interferometry is the technique of reconstructing absolute distance between two surfaces by solving multiple instances of the equation:

    2d = mλ + φ

    where d is the distance between the sensor reference surface and the target, λ is wavelength, and φ is the fractional (residual) interference term. The process for solving these equations is called the Method of Exact Fractions and was developed by Jean-René Benoît in 1898.

    Multiwavelength interferometry enables ZPS to measure the actual distance between the sensor and the target. ZPS performs this technique by using three known wavelengths, measuring the residual interference terms and then solving for m and d. ZPS's algorithms result in a ≤0.5 nm 3σ repeatability. The process is done on all channels simultaneously in a one-second calibration step-heterodyne displacement interferometry is then used to track changes in d thereafter.

    Heterodyne interferometry uses two frequencies of light to generate a constant signal because of temporal interference. This concept is analogous to FM radio, which modulates a carrier frequency to transmit information, resulting in a lower noise floor and better performance. This is why music sounds better on FM radio—the same improvement holds true for position interferometry. ZPS uses an electro-optic modulator to generate the carrier frequency.

    Coupled-cavity interferometers are used in conjunction with low-coherence light sources to measure displacement over short distances. A reference cavity establishes the nominal zero point of the measurement arm of the interferometer. ZPS employs this architecture by introducing a delay between the modulated and unmodulated light. This path delay sets the nominal standoff between the sensor and the target. A thermally stabilized cavity inside the system tracks for variations in the path delay and compensates the data in real time.

    The table shows key performance specifications for ZPS—some of these terms are commonly published by all sensor manufacturers. The resolution is naturally taken to be the indicator of a performance and the metric by which different options are compared. However, with no standard in place, this number means different things when said by different companies. As always, the devil is in the details and it is important to read the fine print to understand what any of these specifications are saying about the performance of the sensor.

    Resolution: what does it really mean?

    Resolution may be the most misunderstood term used to describe a sensor's performance. In some cases, it is just the smallest counting increment from the device—the noise floor may be orders of magnitude higher. In other cases, it includes noise, but either fails to specify the bandwidth or hides it in very fine print. Low bandwidths and rolling averages trade dynamic response for improved resolution. It is always prudent to ask the supplier the bandwidth at which the resolution is specified.

    Zygo uses the term digital resolution to indicate the smallest counting increment available. It is important that this number be below the noise floor (but not too far) to resolve the noise-limited performance of the sensor. With ZPS, we specify the digital resolution (0.01 nm), a bandwidth-independent noise (0.02 nm/√Hz), and the maximum bandwidth (104 kHz). These specifications can all be achieved simultaneously.

    In addition to resolution, some companies are less than direct with other sources of error in their sensors. Zygo understands the total measurement uncertainty of our products and shares this with our customers.

    FIGURE 2. Graphs of performance data from the ZPS sensor show long-term stability (a); nonlinear error, full-stroke range (b); noise, full-stroke range (c); and system repeatability (d).

    Uncertainty: the real performance metric

    The total uncertainty of a sensor system is the truest measure of its performance. Understanding uncertainty can be a graduate-level college course unto itself. The essential aim is to combine all the possible error sources statistically to generate a standard deviation. ISO's Guide to the Expression of Uncertainty in Measurement (also known as the GUM) provides a thorough overview of the process.2 In addition to noise, major sources of uncertainty for position sensors include environmental effects, nonlinearity, stability of length scale, and mounting.

    Bob Hocken, former director of the Center for Nanoprecision Metrology and Distinguished Professor at the University of North Carolina Charlotte, once quipped, "Every machine I ever made was also a thermometer." It is no surprise that temperature changes affect sensor behavior. Noncontact sensors must also consider pressure, humidity, and gas content when operating outside of a vacuum. ZPS has a refractometer accessory that detects the actual refractive index of the air, and automatically compensates sensor measurement values against environmental effects in real time to subnanometer levels.

    Each sensor technology has its own sources of nonlinearity. For interferometers, this typically comes from spurious reflections and manifests itself as a sinusoidal error in the data, earning it the name cyclic error. For other sensor technologies, nonlinearity may come from the limits of the factory calibration. It is important to know that these terms exist and how big they are. ZPS deals with nonlinearity by factory calibration for low-order terms and through a patented active compensation process for cyclic error. The result is a very low residual nonlinearity of ±1 nm.

    The stability of a sensor's length scale is a fundamental consideration for achieving low uncertainty. The length scale for interferometer systems is the wavelength of light used in the measurement. ZPS actively monitors changes in wavelength using thermally controlled cavities housed within the chassis. The system continuously applies compensation for wavelength changes to the measured data automatically. ZPS's specification is ≤1 nm/day, although qualification data shows actual stability to be significantly better.

    Sensor mounting is a consideration often overlooked by designers new to the challenges of precision metrology. Motion of the sensor mount is indistinguishable from motion of the target, regardless of the technology used. It is crucial to identify the sensor's reference surface and keep it fixed over the anticipated thermal and vibration ranges. ZPS's reference surface is on the front face of the sensor, allowing for the design of a tight metrology loop. Other sensors have ill-defined reference surfaces or bury them within the sensor package, adding uncertainty and making it more difficult to produce good metrology.

    ZPS performance

    Despite all the challenges, nanometer-level metrology is possible. The graphs in Fig. 2 show example data of actual ZPS performance. Descriptions of the test conditions are provided below.

    Stability. Zygo evaluates stability by measuring air-spaced Zerodur cavities in a standard lab environment (±0.5°C), with environmental compensation applied via refractometer accessory. To isolate the stability measurement from noise, each data point represents an average over one second. The result is <0.2 nm drift over a four-day period.

    Nonlinearity. ZPS data is taken simultaneously against a helium neon laser-based DMI system. The graph shows the bounds of the cyclic error superimposed on the low-order effects. Low-order nonlinearity comes from the phase change as the target travels through the beam focus. The result is a ≤±0.4 nm nonlinearity over the full measurement range.

    Noise. Zygo uses solid-glass etalons to eliminate mechanical vibrations. The measurements were taken in a nominal lab environment at 5 kHz and then converted into a bandwidth-independent noise figure. ZPS has a tiered specification where the central ±100 μm range has a fourfold improvement in noise compared to the full range.

    Repeatability. Air-spaced Zerodur etalons are used to eliminate mechanical noise. The calibration routine that establishes absolute distance is run repeatedly over the course of several hours. The result is shown to be well below the 0.5 nm 3σ specification for seven different test etalons.

    With a clear understanding of uncertainty, it is easier to compare sensors, even when they employ disparate fundamental technologies. Zygo's precision metrology experience enables production of position sensors like ZPS to meet the uncertainty needs of a wide range of applications.


    1. See U.S. patents 7,636,166; 7,639,367; 7,826,064; and 9,115,975.

    2. See

    About the author: Ernesto Abruña is the product manager for precision position sensors at Zygo Corporation. Originally published in on 10th July 2017

  • Imaging fibres with a SEM: how to obtain a flawless quality analysis

    In our daily life, we make use of a large amount of objects and devices that are produced from fibres. Fibres are usually imaged in a scanning electron microscope (SEM), which provides high-resolution images, elemental analysis, and the possibility of automatically measuring thousands of fibres in mere minutes. But in some cases, imaging fibres with a SEM also presents challenges, as the nature of some fibres might compromise the quality of your analysis. With this in mind, this blog describes how you can obtain a high analysis quality through proper SEM configuration and sample preparation.

    We can distinguish two different kinds of fibres, natural and man-made. Natural fibres can be classified in vegetable fibres, that are for instance based on cellulose and used in the manufacturing of paper or cloth, animal fibres, such as wool, mineral fibres , like asbestos, and biological fibres, including muscle proteins, spider silk and also hair. Man-made fibres range from the synthetic fibres used in the petrochemical industry, to metallic fibres , from fibreglass and optical glass to polymer fibres, which comprises polyethylene, that is the most common plastic used for packaging. Fibres can be woven into textiles or deposited as nonwoven sheets to make filters, insulation, envelopes, or disposable wipes.

    In the production process of these objects and devices, the quality check of fibres plays a role of great importance, where the fibre diameter and size distribution of the fibres are the key parameters. For this step, sophisticated analysis techniques are required to ensure the fibres quality during manufacturing. For example, in the filtration industry, the quality check of the manufactured fibre textiles is of utmost importance to guarantee the filtration efficiency.

    Fig. 1 & 2: SEM images of two metal grids, using 15kV (left) and 10kV (right) beam.

    Imaging of conductive fibres: what is important?

    Conductive fibres such as metal grids can be easily imaged in a SEM without any difficult sample preparation. The specimen containing the fibres is positioned on a pin stub and then placed on a holder that can be inserted into the microscope. For high resolution imaging we recommend high acceleration voltage (10kV or 15kV) and low current, while for composition elemental analysis high current is preferred. Figure 1 shows two examples of metallic fibres in a regular grid, imaged using a 15kV (left) and a 10kV (right) beam.

    Imaging of non-conductive fibres: what is important?

    While imaging conductive samples is, in most cases, rather straightforward, in the case of non-conductive samples the sample preparation plays a crucial role in successfully acquiring informative images. In fact, the imaging in a SEM is done by scanning the electron beam on the surface of a specimen. If the sample is non-conductive, the negative charges build up on the surface, leading to a charging effect, compromising the quality of the analysis. A few different tricks can be applied during sample preparation to limit the effects of charging.

    To limit the effect of charging, insulating samples can be imaged with a low acceleration voltage and low beam current. However, with this method the image resolution deteriorates because of the low electron energy. To overcome this limitation, non-conductive fibres can be coated with a thin conductive film that allows imaging at high acceleration voltage. Figure 2 shows a SEM micrograph of a cotton cloth covered with a 10nm gold film deposited using a sputtercoater. In this example, no charging artifacts are visible and the image quality is preserved. However, because of the 3D dimensionality of fibres, in some cases the sputtered metal might not reach the underlying fibres, which will therefore charge under the electron beam.

    To avoid charging, it is also possible to image non-conductive fibres in low vacuum mode. The presence of air molecules in the microscope chamber allows the electrical charges to find a conductive path and leave the specimen surface. Figure 3 shows the SEM images of a human hair taken in high vacuum (left) and low vacuum (right), using the charged reduction sample holder. In the first image, the charging effect shows up as a brightening of the top surface of the hair, hiding the surface details. In the second image, the charging effects are eliminated by using the low vacuum mode and the surface details are now visible.

    Fig. 3: SEM image of a cotton fabric coated with 10 nm of gold using a 15kV beam.
    Fig. 4 & 5: SEM images of a human hair imaged in high vacuum (left) where charging is visible and in low vacuum (right), using the charged reduction sample holder

    Checking the fibres quality: the tensile test

    Tensile tests are also required in some production lines to check how resistant fibres are when stretched. Performing tensile tests in a SEM allows the user to check, in real time, how the fibres textile stretches under the presence of a force and how the fibres break. Figure 6 shows a strip of paper that was previously covered with 10nm of gold, being torn using the tensile stage.

    Fig. 6: SEM images of a strip of paper being stretched using the tensile stage

    As you can see, there are specific best practices for sample preparation that you can follow to obtain a high quality SEM images.

    About the author: Marijke Scotuzzi is an Application Engineer at Phenom-World, the world’s leading supplier of desktop scanning electron microscopes. Marijke has a keen interest in microscopy and is driven by the performance and the versatility of the Phenom SEM. She is dedicated to  developing new applications and to improving the system capabilities, with the main focus on imaging techniques.



    About Phenom-World

    Phenom-World is a leading global supplier of desktop scanning electron microscopes and imaging solutions for submicron scale applications. Their SEM-based systems are used in a broad range of markets and applications. They continuously invest, develop and integrate their products to help customers improve their return on investment, time to data, and to increase system functionality.

    Lambda Photometrics are the UK and Ireland distributors for sales, service and applications and have been working with Phenom-World for many years. Click here for more information alternatively please contact our Sales Engineers on 01582 764334 or at [email protected].

  • Phenom-World launches the Phenom Pro and ProX Generation 5 SEMs

    The brand new Phenom Pro and ProX Generation 5 desktop SEMs are the high performace desktop SEMs that provide accurate and reliable results for a wide range of applications from materials science and industrial manufacturing to electronics, life sciences and many more.

    What is NEW with Phenom SEMs Generation 5?

    • Enhanced imaging thanks to new electronics and an improved lens
    • Imaging of materials that are very sensitive to beam damage
    • Excellent imaging quality of non-conductive samples thanks to a long-lifetime, high-brightness CeB6 source
    • Wide range of detectors for applications that require material contrast as well as surface-sensitive information.

    Click here for further information or contact our Sales Engineers on 01582 764334.

  • NUWPEC Approved Framework Supplier

    Lambda Photometrics is an approved supplier within the National Universities Working Party on Electronic Components. The company was awarded Lot 3 in the current framework agreement: Test & Measurement Equipment. Feel free to call us on 01582 764334 for exact details of the supplier discounts we offer for your institution.

    This framework agreement is available to members of a significant number of university purchasing consortia. These bodies include NWUPC (North Western Universities Purchasing Consortium), LUPC (London Universities Purchasing Consortium) and SUPC (Southern Universities Purchasing Consortium).

    These consortia work collaboratively in conjunction with framework agreements to offer their members access to the highest quality products, goods and services at the most competitive prices, to save time and resources, and to access professional support from fellow members.

    See below for the purchasing consortia for which Lambda Photometrics is listed as a supplier:

    North Western Universities Purchasing Consortium

    Southern Universities Purchasing Consortium

    Crescent Purchasing Consortium

    Higher Education Purchasing Consortium, Wales

    Advanced Procurement for Universities and Colleges

    North Eastern Universities Purchasing Consortium

    London Universities Purchasing Consortium

    The University Caterers Organisation

    To speak with a Sales/Applications Engineer please call 01582 764334 or click here to email

    Lambda Photometrics is a leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Electronic/Scientific and Analytical Instrumentation, Laser and Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics and Microscopy.

  • New products, 3.39 Interferometer on show and ZeGage demo system for on-site demonstration

    Zygo Verifire 3.39 Infrared Interferometer

    After presenting the Zygo Verifire 3.39 Infrared Interferometer at the laser exhibition in Munich, Zygo Germany have the system available in their Weiterstadt demo lab for customer measurements and system demonstrations.

    The system will be only be available until the middle of August. Please let us know soon whether you or your colleagues would be interested in a demonstration or sending test samples for measurement.

    Zygo ZeGage Plus demonstration system coming to Lambda soon

    We will have the Zygo ZeGage Plus Non-Contact Optical Surface Profiler available for on-site demonstrations soon. With a range of objectives available from 1x to 50x we can measure most surfaces of interest.

    The ZeGage Plus profiler can measure a wider variety of surfaces – ranging from very rough to super smooth, with sub-nanometer precision, independent of field of view. Surface finishes may include ground, honed, lapped, polished, and super-polished on materials such as glass, ceramic, and metal. Contact us to book your demo.

    New high lateral resolution laser interferometers

    Zygo have introduced the VeriFire HD and VeriFire HDX Interferometers.

    The Verifire HD is designed with modular options so you can configure your system with the exact mix of options you need. Some available configuration options are:

    • Point source or coherent noise reduction (artefact suppression)
    • 5.3 or 1.4 megapixel camera
    • Fixed zoom, or discrete motorised turret zoom (1x, 1.7x, 3x)

    The Verifire HDX system has an all-new optical design that was rigorously engineered to support pixel-limited performance for its 3.4k x 3.4k (11.6 megapixel) sensor, delivering enhanced imaging which reveals surface features that have been difficult to discern with lower resolution interferometers. This ultrahigh spatial resolution doesn't come at the expense of speed. The system operates at a frame rate of 96 Hz, at full resolution – up to 10X faster than other high resolution interferometers that can have limited capability due to noise entering the much slower measurement.

    ZPS - Absolute Position Measurement System

    ZYGO's new ZPS™ System measures absolute position using ultra-compact optical sensors that are easily integrated into high-precision applications such as deformable mirrors and lens positioning. The optical sensor system provides up to 64 synchronised channels of high-precision, non-contact, absolute position measurement over a range of 1.2 mm. Measurement resolution is 0.01 nm with ≤ 1 nm/day measurement stability.

    The optical sensors do not generate heat and are insensitive to electromagnetic interference, making the ZPS System ideal for high-precision applications that may be affected by these factors. The ultra-compact sensors connect to the compact centralised enclosure via fibre optic cables.


    Demonstration systems at Lambda available for sale

    We have a VeriFire QPZ Interferometer and a Nexview Optical Surface Profiler at Lambda available for demonstration and also available for sale. The QPZ is equivalent to the new VeriFire but with the old style wired remote control.

    The Nexview is the top of the range Optical Surface Profiler from Zygo and can measure super-smooth samples using SmartPSI technology, measure in colour without sacrificing metrology capability and is automated for ease of use for users. Contact us for demonstrations or price enquiries.

    To speak with a Sales & Applications Engineer please call 01582 764334 or click here to email.

  • Scratches and Digs – measure on curves and large areas now!

    Scratch/Dig measurement systems from Savvy Optics and Dioptic have begun life looking at flat surfaces up to 100mm square or 45mm diameter respectively.

    Recent advances (through demand) now allow for measurements to be made over large flat areas using the SavvyInspector SIF-16 which can cover an area of 200mm x 400mm. On parts that larger, full part mapping is essential. The new “autoscan” feature allows unmanned scanning and documentation of the entire optical surface as the system steps and photographs the entire part in 9 x 12 mm position labelled images and puts all images in a folder for review by an inspector.

    The ARGOS system from Dioptic can now measure curved surfaces also. They have shown that they can measure a 1” diameter plano-convex lens of focal length of f = 150mm using a 4° tilted camera setup. This method is fast and less prone to errors.

    The ARGOS system can also measure edge chips and coating holes. It can also be automated for high throughput and productivity. There is also a version for measuring fibre cable end caps.

    The surface recognition performed by ARGOS recognises the tiniest defects during a running production process. The detection device for the surface recognition shows holes down to 4 µm and scratches that are as small as 1 µm wide. In addition to holes and pits, other recognisable surface defects include sleeks, streaks, coating defects, orange skin, bubbles and inclusions in the material that are close to the surface, grey coloration/blurriness and damage on the edges. All defects are shown on the screen.

    To speak with a Sales & Applications Engineer please call 01582 764334 or click here to email.

  • Technical and Application Notes for the SRS BGA244 Binary Gas Analyser

    Stanford Research Systems BGA244

    The BGA244 Binary Gas Analyser from Stanford Research Systems (SRS) is a new product harnessing the fundamental physical principles of acoustic resonance to measure the speed of sound in a gas mixture and provide gas ratio measurements with errors as low as 100ppm. This technique has advantages over conventional thermal conductivity binary gas analysers with SRS’ implementation providing a dramatic improvement in performance and value:

    • Ten times better accuracy
    • Thousand times better stability
    • Lower cost of ownership due to reduced installation cost and maintenance
    • Greater flexibility with ~500 pre-calibrated gases and no recalibration to change gases

    To learn more about the physical principles behind the BGA244, its use in many diverse applications and the comparisons with other binary gas analysers, the following series of technical/application notes are available. Simply click on each link to download the document you require. For further information or to ask any questions, please do contact us on 01582 764334 or click here to email

    Tech Note - BGA244 Physics Overview

    Tech Note - Comparing Thermal Conductivity Analysers with the BGA244

    Tech Note - BGA244 vs Composer Elite

    Tech Note - Using Pressure Transducers with the BGA244

    Tech Note - Gases Measured by the BGA244

    Tech Note - BGA244 Diborane in Hydrogen

    Tech Note - BGA244 Measuring Mixtures of Nitrogen and Hydrogen

    Tech Note - BGA244 Long Term Stability for Measurement of Trimethylindium

    Tech Note - BGA244 High Concentration Ozone Measurements

    Tech Note - BGA244 Creating User Defined Gases

    Tech Note - BGA244 Monitoring Gas Quality in Helium Recovery Systems

    Tech Note - BGA244 Carbon Dioxide and the Relaxation Correction

    Tech Note - BGA244 Measurement of Argon-Air and Krypton-Air Mixtures for Insulating Windows

    Tech Note - BGA244 Measurement of Methane in Argon

  • Available now: The first Sony Pregius CMOS cameras with 1 micron exposure time

    Lambda Photometrics are pleased to announce the first CMOS cameras from Baumer with an exposure time down to 1µs in the mainstream segment of digital industrial cameras. The CX models including the second generation of Sony Pregius sensors feature exposure times ranging from 1µs to 60s. Available with up to 12 megapixel resolution, they are ideal in tasks at high light intensity such as laser welding and will minimise blur in high-speed applications like pick and place. Having extended the application possibilities of CMOS cameras, Baumer has closed a gap where previously CCD sensors were required. Samples are available now; production starts in the third quarter of 2017.

    Pushing further toward best-in-class in terms of short exposure times, the CX cameras with 29x29mm housing design perform perfectly in hot environments due to their high operating temperature capability of up to 65°C. Additionally, they feature 1000fps with ROI (Region of Interest) and an excellent dynamic range of 71dB. As a result of their high resolution merged with excellent image quality, the GigE and USB 3.0 cameras master virtually any task in various industries which place the highest demands on image details and throughput.

    Further information on our Machine Vision camera series click here.

    To speak with a sales/applications engineer please call 01582 764334 or click here to email

    Lambda Photometrics is a leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Electronic/Scientific and Analytical Instrumentation, Laser and Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics and Microscopy.

  • The BGA244 - a new 0.1% accuracy Gas Analyser for single and binary gas mixtures

    Stanford Research Systems BGA244

    The BGA244 Binary Gas Analyser from Stanford Research Systems quickly, continuously and non-invasively determines the ratio of gases in a binary mixture, or checks the purity of a single gas with better than 0.1% accuracy.

    • <0.1% accuracy
    • 10ppm resolution
    • 4Hz measurement rate
    • USB, RS232, RS422 & software
    • Continuous in-line operation
    • Analogue I/O, Event relays

    The speed of sound in a binary gas mixture depends on temperature, heat capacity, and molar mass of the mixture. By precisely measuring the speed of sound and temperature, and knowing the thermodynamic properties and molar masses of the gases, the SRS BGA244 determines the exact composition of gas mixtures.

    The BGA244 provides a hundred fold improvement in stability, accuracy and resolution over thermal conductivity analysers. It operates without lasers, filaments, chemical sensors, optical sources, separation columns, reference gases, or reagents, and runs virtually maintenance-free. It also lets you choose from 500 gases, enabling you to measure thousands of mixtures.

    The BGA244 does not require zero or span calibration to achieve 0.1% accuracy. This eliminates the need for reference, zero and span gases, plus the valves, labour or software needed to perform them; leading to a lower cost of ownership. This, plus the improved accuracy and wide range of gases, dramatically improves the value proposition for the BGA244 when compared to other analysers.

    The BGA244 is ideal for a host of applications including binary gas blending, PSA (pressure swing adsorption), helium recovery, ozone purity, dopants and carrier gases, industrial gas processes and general research where precise and reliable measurements of gas mixtures are essential.

    Click here for further information.

    To speak with a sales/applications engineer please call 01582 764334 or click here to email

    Lambda Photometrics is a leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Electronic/Scientific and Analytical Instrumentation, Laser and Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics and Microscopy.

  • Applications of Scanning Electron Microscope in Pharmaceutical Research Field

    Pharmaceutical research involves creation of new drugs or continuous improvement of existing drugs. This versatile research topic is a broad field of study dealing with an increasing number of challenges, owing to new pathogens emerging constantly and known pathogens becoming increasingly resistant to existing drugs.

    Since more information is needed, the use of advanced tools, such as scanning electron microscopes (SEMs), has been shown to be very powerful in various applications in the pharmaceutical field. In pharmaceutical research, SEMs are used for powder imaging and analysis, to gain insights into cellular interactions with new drugs, and for applications in the most complicated cancer treatments.

    This article discusses a few examples to illustrate the successful application of SEMs in research facilities across the world to develop novel and more powerful drugs to treat diseases.

    Figure 1. An example of mammalian cells observed with SEM

    Superporous hydrogels

    A research team at AIMST University in Malaysia is involved in the development of a new class of superporous hydrogel beads. Hydrogels consist of a network structure of cross-linked hydrophilic polymers that are capable of absorbing water in large amounts without dissolving.

    These beads are employed as carriers in pharmaceuticals for controlled drug delivery based on their biodegradation and swelling abilities. Since a targeted drug delivery eliminates side effects on other cells or tissues, it helps achieve easier and faster regeneration.

    With developments in research, and the increasing need to develop enhanced and highly performing drugs, the researchers have developed a new class of hydrogels with rapid swelling capacities - the reason for the name “Superporous Hydrogels”. Here, the researchers examined the surface structure and porosity of the dried beads using a SEM.

    Cancer drug research

    A new kind of approach was used in cancer drug research. It was found that aromatase, an enzyme responsible for determining the final sex phenotype of fish, was also playing a key role in the progression of breast cancer. Therefore, in a study, researchers used aromatase inhibitors for breast cancer treatment.

    In fish, androgens are irreversibly converted into estrogens by aromatase enzymes, thereby establishing the embryo’s gender to female. Researchers are showing more interest to study male fish than female fish of this species because male fish generate anti-aromatase in large quantities.

    Like Nile tilapia which gained attention as a source of food worldwide, aromatase obtained from this fish was the subject of interest for researchers looking for aromatase inhibitors.

    Nile tilapia microsomes were used to study the enzyme activity of aromatase inhibitors. They are vesicle-like fractions of the endoplasmic reticulum (ER) present in healthy living cells. In this study, hepatic microsomes were prepared from Nile tilapia and their morphology was explored using a SEM.

    The proliferation of cancer cells was investigated using HepG2 human hepatoma cells and MCF-7 human breast cancer cells. The study results revealed that the growth of both cancer cell lines was efficiently inhibited by a specific anti-aromatase present in microsomes.

    For a successful cancer research, the morphology of tissues needs to be analyzed and understood. At present, this can be achieved using the correlated light and electron microscopy technique.

    Figure 2. Correlated light and electron microscopy image of HeLa cells

    Development of antibacterial powders

    Antibiotics are excessively used and as a result, the numbers of antibiotic resistant bacteria are constantly increasing. Hence, researchers are seeking new ways to find the presence of bacteria on medical devices to prevent nosocomial infections or hospital-acquired infections as much as possible. Extensive research is going on in the development of new antibacterial powders.A study revealed that pathogens present on polymer medical appliances can be very efficiently destroyed when ZnO and Ag-ZnO crystals are added to antibiotics. Here, a SEM was used to analyze the elemental composition and morphology of the crystals before using them for further experiments.

    Figure 3. Pharmaceutical crystals observed with SEM
    Figure 4. Pharmaceutical components including crystals observed with SEM


    In summary, scanning electron microscopes are a very polyvalent tool that can be used for various research activities in the pharmaceutical field. It helps understand the morphology of the component of interest and highlights the effect of interactions with its environment.


    1. Development and in vitro Evaluation of New Generation Superporous Hydrogel Beads (SPHBs) Containing Fluconazol. Kumar et al. Journal of Pharmaceutical Sciences & Research; Vol. 5 Issue 12, p259 (2013)
    2. Investigation of anti-aromatase activity using hepatic microsomes of Nile tilapia (Oreochromis niloticus). Pikulkaew et al., Drug Discoveries and Therapeutics (2017)
    3. Antibacterial Powders for Medical Application Prepared by Microwave Hydrothermal Assisted Synthesis. Kunitka et al,. Nanoscience and Nanotechnology, 6(1A): 88-91 (2016)


    About Phenom-World

    Phenom-World is a leading global supplier of desktop scanning electron microscopes and imaging solutions for submicron scale applications. Their SEM-based systems are used in a broad range of markets and applications. They continuously invest, develop and integrate their products to help customers improve their return on investment, time to data, and to increase system functionality.

    Lambda Photometrics are the UK and Ireland distributors for sales, service and applications and have been working with Phenom-World for many years. Click here for more information alternatively please contact our Sales Engineers on 01582 764334 or at [email protected].

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