In this case, the idea was to design a support with several degrees of freedom (3+z). In order to place a housing with a capillary in the alignment of an IR laser, this in order to generate a time resolved X-ray beam. The infrared laser beam is stopped by a thin silicon sheet and the X-ray beam continues its path to a toroidal mirror, allowing beam to be focused on the sample to be analyzed.
Adjustable angular support for X-rays transmitter housing
Toroidal mirror holder
In conjunction with the above design, this mount allows a toroidal mirror to be aligned to focus an X-ray beam on a sample. This assembly, placed in a high vacuum, is driven by micrometric movements remotely controlled.
The design is still in progress, indeed other mechanisms have yet to be designed: filter carousel support, sample support, path reverser control
Dual view inverted SPIM or DiSPIM
In this case, the aim was to develop an evolution of the SPIM microscope (already in use) to achieve higher resolutions.
The diSPIM is an implementation of the Selective planes illumination microscopy (SPIM) which allows double views of the sample, mounted on an inverted platinum microscope. This mounting can be used in both operating modes (SPIM and/or DiSPIM)
(SPIM, also known as light sheet fluorescence microscopy or LSFM because it uses a sheet or plane of light to illuminate the sample perpendicular to the imaging direction)
The mounting is as follows: two objectives are placed at right angles above a horizontally mounted sample in a fastenable, vertically motorized, vertical mount. Each lens has an angle of 45 degrees to the vertical. A sheet of light is created from one lens and imaged using the other. Underneath the object holder plate is also a lens, in a vertical position, in the optical axis of the sample, and equipped with a camera.
A series of images are collected by moving the light sheet through the sample. For some applications, 3D information from a single view or series is sufficient (SPIM mode).
For dual-view systems, the role of the two lenses is reversed, to collect another series from a perpendicular direction, and then the two data sets can be combined by computation to produce a 3D data set with isotropic resolution (solving the poor axial resolution problem of the SPIM).
The diSPIM therefore has two optical paths (typically symmetrical), including two scanners and two cameras. Various open source and proprietary software packages are available for data acquisition and processing. Most of the underlying microscope hardware is identical regardless of the system integrator and software used.
The choice of diSPIM lenses is limited because they must be focused on an identical point without colliding. The most commonly used objectives for diSPIM are the X40 immersion lenses with an NA of 0.8. Single-track systems (SPIM) have much more flexibility because the illumination lens can be a long-distance working objective. In most cases, CMOS cameras are used for SPIM or DiSPIM imaging (here a Hamamatsu Orca camera). Galvanometric mirrors are commercial models. The lower lens (the inverted microscope) usually has a lens magnification of less than X40, and a less expensive camera to locate an area in the sample.
The benefits over SPIM microscopy are as follows:
Like other techniques using the light sheet, the diSPIM illuminates only the focal plane, so it is ideal for imaging cells and living organisms, because it minimizes the effects of photo-bleaching and photo-toxicity.
Compared to traditional confocal systems, the improvement in axial resolution is of the order of 2x, and greater than 10x in reduction of photo-bleaching. A major advantage of the diSPIM compared to other implementations of the light sheet technique is that the sample assembly is extremely simple, similar to an inverted platinum microscope. Most often, the specimens are inside a Petri dish, placed on a holding system. In addition to being useful for locating samples, the lower lens can be used for photo-manipulation or other experimental techniques. It can also be used to provide a third independent view of the sample.
“Drawer” frame support for gas cylinder type B20
The aim was to design a chassis to secure the support and storage of a standard gas cylinder, type B20, under the aluminium profile chassis of the so-called BMF experience.
The frame allows the bottle to be stored in a horizontal position, with a blocking in position. the “drawer” is equipped with a mechanical lock, allowing a user to handle the cylinder when replacing it.
UTEM shielded support adapter
Tungsten tube holder adapter (passive X-ray shielding, W85cu15 alloy). This safety system is mounted on the column of the UTEM microscope (CuZn40Pb2 brass adaptor, covered with 3 mm lead passive shielding)
Sample changer with carousel (extractable sample holder)
The aim was to design an improvement of the sample passage device for X-ray scattering lines derived from synchrotron radiation. The original mounting does not allow the sample holders to be exchanged quickly enough despite the ejector integrated in the mechanism.
In order to remedy this problem, I designed a new device, again using a Geneva wheel mechanism identical to the previous one in terms of dimensions, thus allowing to recycle the existing motorization and automation.
This assembly is a 12 station support cylinder, using an automatic locking bayonet to position the samples in the axes of the 12 stations of the Geneva wheel. The disassembly and replacement of the cylinder is obtained by rotating a single knurled knob, allowing both unlocking and ejection.
The system is entirely made of 2017A aluminium alloy, the precision of the parts, assembly and positioning is achieved by 3+1 axis CNC machining.
- use of a standard electric motor
- use of a single position sensor
- drive and locking in position thanks to a single mechanism
- angular positioning accuracy and repeatability of the mechanism
- ejector and locking of the 12 cells thanks to a cylinder supporting the samples
- bayonet cylinder locking system (single control for insertion and removal)
- repeatability and speed of execution of the replacement of a block of 12 samples
- preparation in masked time of a series of several barrels of 12 samples.
Centrifuge rotor extraction system. In this case, the heavy rotor engaged on the drive cone of the centrifuge must be extracted effortlessly. To do this, I designed a claw grapple with a holding spring, which is self-tightening during the traction of the motorised hoist, to which the mechanism is attached.
Static and dynamic light diffusion resolved in time
We develop an instrument for static and dynamic diffusion of light under flow in plane/plane geometry. Accessible scattering angles range from 20 to 160 degrees. The incident beam is perpendicular to the plane of flow and the scattered beam is collected by an optical fiber placed on a goniometric arm whose centre of rotation is inside the sample and coincides with the centre of a hemispherical lens to avoid refraction of the beam at the glass/air interface at the exit of the shear cell. In addition, the shear cell as a whole can be translocated while keeping the diffusing volume fixed, in which coincide at the same time the center of the lens, the centre of rotation of the goniometric arm and the focal point of the incident beam. This apparatus will be used to study the static and dynamic structure factors of colloidal suspensions concentrated in the vitreous phase, in order to carry out spatially averaged measurements when the samples are not ergodic.
This assembly (parameter setting, piloting, servo drive and operation) will be the subject of a thesis in 2016.
Cooling support for a magnetic field application coil
The idea was to design a compact coil support to apply a magnetic field to a sample for a confocal microscope. This support also makes it possible to evacuate the heat emitted by the coil during the passage of the current, incidentally this also makes it possible to obtain a larger field strength.
the parts are mainly copper cuc1 and brass cuzn40, brazed.
AFM tip holder for near-field microscopy
The aim was to model an experience of near-field microscopy (type SNOM) in order to produce 3d renderings, as well as to design an integral hood with an easily removable section for quick access to the adjustable elements. On request, I also designed a state-of-the-art AFM support allowing precise positioning of the tip in the laser axis and adjustable angle between 0 and 15° (the axis of rotation being coaxial with a vertical axis passing through the tip end).
Variable magnetic field applicator
The aim was to design a very compact mechanism for applying a magnetic field to a sample for characterization on an AFM. The application of this magnetic field is modulated thanks to a soft iron polar piece with three pierced branches. These cavities can be occupied by cylinders, also made of soft iron, which, by sliding, restore all or part of the effective cross-section of the polar piece in contact with the neodymium boron magnets (about 0.9T each). The resultant field at the end of the principal polar piece is about 1.8T.
Light Sheet fluorescence microscopy, or Single plane illumination microscopy
The aim was to design the components of a light sheet microscope:
- a physiological chamber in an aqueous medium, supporting the objectives
- a laser and galvanometric mirror support
- a mechanism for positioning and rotating a capillary in the plane of the light sheet
Test tube drive holder for DLS ALV
AFM tip holder for FIB machining
SAXS Cell Holder and Clamping System
Rapid positioning and clamping system to fill a sample cell without the solvent (THF) damaging the joints, causing a leakage of the compound to be analyzed.
Used mainly with cells intended for SAXS analysis (Small angles X-rays Scattering).
Atomic Force Microscopy and Spectroscopy : AFM-DeNano
Experiment of sample manufacturing by secondary vacuum evaporation, with vacuum transfer system, coupled to a commercial atomic force microscope, its sample holder is modified, it also includes an optical breadboard allowing to excite the sample with several types of coherent lights.
This equipment is built around an atomic force microscope (AFM), coupled with an ultra-high vacuum preparation chamber designed for the preparation of metal and molecular surfaces, controlled deposits of atoms, molecules and nanoparticles, and specific modifications of levers and tips. The chamber is also equipped with an ion bombardment barrel and a sample holder with variable temperature (90 K – 1600 K). Samples and tips are transferred to the microscope without exposure to air. Measurements are possible depending on temperature, magnetic and electrical field, and a wide range of partial pressures of different gases.
The microscope is used for AFM, FFM, MFM and STM imaging and EFS, IFS, AFS, MFS spectroscopy. It allows the manipulation of nanostructures on surfaces and different methods of local nanolithography. The resolution extends to the femtoNewtons. A high-grade magnetic field gradient is set up using nanometric magnetic circuits mounted on sample holders.
This montage is currently used, and is the subject of several theses, with publication.
X-ray scattering line : Inel3-S1-S3
X-ray scattering experience at small and large Bragg angles, using the point and linear outputs of the RX tube, with stainless steel vacuum barrels, retractable wells, 2D meter (S1) and proportional gas meter (S3).
These lines are likely to use three types of ovens:
- capillary and film furnace (S1)
- magnetic furnace (1.2T) (S1)
- droplet level incidence furnace (S1)
- flush incidence furnace for flat samples (S3)
- These furnaces are currently used on synchrotron lines (SOLEIL-SWING)
Cross optical mounting (X-ray scattering line INEL3-S1)
In order to enlarge the measuring window to very small angles on the diffusion line of the INEL3 X-Ray, without displacement of the limit at wide angles, we have designed a new optics:
The chosen technical solution combines 2 parabolic W/Si multilayer mirrors (Osmic©) mounted in the crossed position (KirkPatrick Baez) to allow working in near-parallel beam conditions. The optical assembly carried out in the laboratory includes direct attachment to the point output of a CGR sheath, adjustments in position and inclination of the two mirrors, a set of independent lip slots and an adjustable collimator in position, in conjunction with the housing of the attenuators. The beam size measured at 115 mm and 940 mm of the specimen holder, respectively, is increased from 0.9 mm to 1.5 mm. With a 3 mm well, it is therefore theoretically possible to measure 600 Å repetition distances, well beyond the 55 Å reached with the collimation optics of the previous mounting.
drop furnace for grazing incidence x-ray scattering
Among the methods of orientation described in the literature, we have retained the one invented and developed by Siegmar Diele at the Institute for Physical Chemistry of the Martin-Luther-Universität Halle-Wittenberg. The sample is deposited as a free drop on a glass plate in the isotropic phase. As the transition passes, liquid-crystalline domains are formed with the columns or smectic layers parallel to the interfaces with air and substrate. The top of the liquid crystal drop is then brought to a low incidence with the spot beam and eventually moved and directed into the beam.
To make this device, we started from an oven recovered on a half read head of DSC7 Perkin-Elmer that we integrated on a rotary radiator, cooled by a circulation of thermostatic liquid. To allow rotation, the power supply is connected via 2 ball bearings and the Pt13 sensor of the DSC furnace via rotating contacts (Grumann-northtrop©). A converter of the Pt13 signal supplied by the oven to the standard Pt100 signal has been designed and built in the laboratory (also thermostated housing). The phase angle control electronics and control and piloting software developed in the laboratory are the same for all furnaces, by adjusting the input voltage. For the drip furnace, the stability of the regulation is about 0.1°C and the heating and cooling speeds are about 200°C/mn (at 100°C).
Universal Owen for capillaries and sealed vessels
The aim was to design and build a heating oven capable of holding samples in the form of capillaries or sealed vessels. This equipment is intended to be integrated on an X-ray scattering line. The setpoint temperature is adjustable from room temperature to 200°C. The regulation accuracy around the setpoint is in the order of a few hundredth of degrees Celsius at 200°C.
I designed a modular brass furnace, based on a heating element that can be wound, 1.5 mm in diameter and a length of one and a half metres. The element is wound in spiral form, then rolled into a cylinder on 2 thicknesses, respectively the back side, and the circumference of the furnace, so as to obtain a fully heated cylinder around the sample.
The furnace has a cavity to hold the capillary support of 1 to 2 mm diameter capillaries and the sealed vessel for liquid sample. The oven is closed by a quick-release door.
In order to achieve precise regulation, the entire furnace is bolted to a water-jacket by means of a base plate and coupling washers whose dimensions and material have been carefully chosen, in fact only a precise dosing between the cold and hot springs makes it possible to obtain the desired regulation.
The water-jacket is also made of brass, the three elements that make up the water-jacket have a helical cavity, allowing the coolant to circulate in the cooler’s mass: from the inlet nipple to the outlet nipple. The fluid used is thermalised water, thus contributing to the stability of the temperature measurement. The water-jacket is like the oven, closed by a quick-disassembly door.
The main characteristic of the oven is its precision (quality sought after), to the detriment of its dynamics (30 min to reach 200°C stabilized, 1 hour to cool down to the ambient temperature).
Traction Force Microscope (TFM)
We have developed a microscope frame for mounting Traction Force Microscopy. The constraint imposed was a very high mechanical stability over times of several hours. The microscope is placed in a thermostated enclosure at 37°C and fixed on an optical table.
The sample-supporting plate is thermally isolated from the optical table (which is a cold source) by the use of ceramic (Macor©) with a very low thermal conductivity but a coefficient of thermal expansion very close to stainless steel (3016L) used for the rest of the frame.
The lens is attached to the specimen holder plate, so as to minimize its displacement with respect to the specimen, under the effect of thermal fluctuations. We thus obtained a maximum value of the mechanical drift of one point of the sample equal to 10nm/10h.
Magnetic Tweezers Microscope
We have developed a tool (magnetic clamps) for the micro-manipulation of DNA molecules.
This technique allows a controlled force (and possibly torsional torque control) to be applied to a DNA molecule while measuring its extension. The light source is a super luminescent diode.
This device uses super-paramagnetic balls with a diameter of about one micron, one end of the molecule is bonded to the magnetic ball, while the other end is attached to the surface of the sample (a glass slide). The ball is magnetized by a magnetic field from a pair of cubic magnets (5 mm side) arranged 1 or 2 mm apart; the sample is illuminated through the magnet holder. This inverted platinum microscope is equipped with an oil immersion objective mounted on a piezoelectric feedback loop. The position of the ball is recorded in real time by video acquisition with a resolution lower than nm, the bandwidth is 405 Hz.
In order to ensure dimensional stability of the mechanical elements of the device (platinum, support, sample, etc.), these are made of 316L stainless steel machined in the mass. The entire microscope is placed under a protective (acoustic) cover, placed on an optical table.
Vacuum rotary Evaporator/Pill Holder Adapter
Design of an adapter to mount a pillbox directly on the n°1 cone of a rotary evaporator. No contact between synthetic product and metal, several dimensions of pillboxes possible.
Carousel sample changer
Design of a sample changer, mainly intended for use on intense X-ray scattering lines (synchrotron). The 12-station carousel-type pass-through device uses a genova wheel mechanism (or Maltese cross), with several advantages:
- use of a standard electric motor
- use of a single position sensor
- drive and locking in position thanks to a single mechanism
- angular positioning accuracy and repeatability of the mechanism
- ejector and locking of the 12 cells thanks to parts obtained by additive manufacture
Sample holding system for neutron scattering line (quartz vessel)
Quick hold and quick-release clamping system for sealing a quartz sample cell. The clamping shoe (ptfe) moves linearly without rotation.
Used primarily with cells for neutron scattering analysis (PSI, LLB).
Siemens X-ray scattering line
X-ray scattering experience, at small and large Bragg angles, using the linear output of the X-ray tube, with well, and curved counter (S2).
This line uses the universal heating oven for capillaries and sealed vessels.
Mechanism for generating an electric field
Studies of quadratic non-linear effects in ONL molecules of push-pull type:
The aim is to set up a microscopy system capable of measuring the quadratic effects in ONL molecules under electric field by corona effect. Indeed, we have designed a module of the EFISH type (electric-field-induced second harmonic), adaptable to any microscope, capable of orienting ONL molecules by corona poling in order to study the signal of the generation of the second harmonic among other things according to the applied electric field and the orientation of the molecules.
Set of characterization mechanisms using two types of force transducer