Force controlfornanohandling insideScanningElectronMicroscopes - PowerPoint PPT Presentation

TC-ANH Force controlfornanohandling insideScanningElectronMicroscopes Daniel Jasper Division Microrobotics and Control Engineering 1 Technology Cluster Automated Nanohandling Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Contents ► Introduction ► Limits of currentSEM-basedtracking ► Trackingwithbeamcontrol ► Isthe SEM a perfectsensor? ► Force sensinggripper ► Conclusions and Outlook Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 2 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Introduction ► Why do weneed a global sensorfornanohandling? ► Insufficient robot / sensoraccuracy nm accuracy needed ► Buy betterrobots! ► But: MorethanthreeDoF? Tool Specimen ► Imprecisemounting / manufacturing Robot Robot ► Do calibration! A B ► But: Usingwhatreference? Someconnection ► But: Feedingsystem? ► Drift several cm ► Do drift compensation (AFM..)! ► But: Whatifmoretoolsarerequired? Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 3 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Introduction ► Requirement: Nanoobjectsmustbedetectable ► Availalbe global sensors: ► Scanning Probe Microscopes ► Seriousspacerestrictions, tinyworkingspace ► Speed ► Transmission ElectronMicroscope ► See SPM ► ScanningElectronMicroscope ► Usable ► Key challenge: Efficientobjecttracking ► Otherideas? Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 4 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Limits of currentSEM-basedtracking ► Image acquisitionslow ► Distortedmovingobjects ► Image processingslow ► Limited update rate ► Significantdead time ► Idea: Do notacquireimages Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 5 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Idea ► Interpolation in high-resolution linear encoders ► Required: Sine and cosinesignal Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 6 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol ► Sine / cosinevaluefrom image data Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 7 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol ► Whatifthesignalisnotexactlysine-shaped? ► Sine/Cosineinterpolationwiththelissajousplot Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 8 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol ► Scanning a specific, grid-like target structure ► Standard SEM calibration chessboard Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 9 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol ► Results of 10 measurements on each step ► Accurate measurements ► Sub-pixel resolution ► Low noise ► 16 nm step visible Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 10 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol ► Advantages ► Computationally simple ► Robust against noise ► Robust against changing brightness / contrast ► Sub-pixel accurate ► Disadvantages ► Needs target pattern ► Needs acquisition of complete images ► Limited to a number of pixels Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 11 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol ► Line-scan is sufficient for position detection ► Scanning a square on the target ► If target moves, adjust the scanned square Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 12 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Movementdetection ► Target moves ► Signals change correspondingly ► New target center position can be calculated exactly with sine/cosine interpolation ► Resolution/Noise <10 nm Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 13 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Using a real target ► Target: SEM calibration grid ► Smallest square: 1 µm ► Works without exact sine waveform ► Beam-induced deposition visible ► Drift? Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 14 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Results ► Defocused image ► Unaffected as long as pattern still visible Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 15 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Results ► Brightness and ► Rotating contrastchange ► No influence on x and y ► Outliers Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 16 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Tracking with beam control – Results ► Different specimen currents ► Reduced sharpness: Not important, no edge detection ► Better signal-to-noise ratio: Less noise Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 17 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Results ► Magnification ► Almost identicalresults on 1000x and 10000x magnification Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 18 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Long rangescan ► 1000x magnification ► Working range: ~200 µm ► Little to no impact on noise and resolution Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 19 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Trackingwithbeamcontrol – Properties ► Can measure x, y and φ ► Update rates up to 1 kHz and more ► Noise <10 nm ► Immune to brightness/contrast/focus changes ► Long-range scanning (±100 µm) ► Four orders of magnitude ► Combination with imaging possible ► Multi-tasking / Scheduling ► E.g. Measure position after each line of image scan Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 20 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH So, isthe SEM a perfectsensor? ► No! ► Inherentlyserialprocess, no batch-processing ► Similar to otherrequiredtechnologies ► Increasethroughput ► Hard to integrateintostandardmanufacturingline ► Vacuum � Airlocksnecessary ► Feedingsystems to putobjectsontonanorobots ► ... ► But: Excellentforprototyping ☺ By esec semiconductor Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 21 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH So, isthe SEM a perfectsensor? ► Time-variantrelationbetween SEM and worldcoordinates ► But: 99% of operationsonlyrequired relative coordinates ► Complextargetpatternsneed to becreated ► Canbesimplified y ► Work in progress: Automatically find objectmodel and edges y ► Trackingworks in plane, butwhatabout 6 DoF ► Z/Height-informationrequired ► Work in progress: Focus information, Stereoscopic SEM imaging ► Position tracking good, but I need force detection x SEM ► Visual force detection x world Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 22 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Simplifiedscanningpattern ► No rotation measured ► Onlyonepoint-shapedpatternrequired Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 23 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Force-sensinggripper Gripperdesigned and fabricatedby DTU, Denmark Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 24 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Pushing a CNT againstthegripper Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 25 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow

TC-ANH Pushing a CNT againstthegripper ► 10-fold averaging ► 100 Hz update rate ► Stiffness: ~4 N/m ► Max.: 12 nm ≅ 48 nN ► Noise: 2 nm ≅ 8 nN ► Carefullstiffnessselection: ► Too soft: no gripping ► Toohard: lowresolution Division Microrobotics and Control Engineering Daniel Jasper, ICRA 2009 26 Technology Cluster Automated Nanohandling 17.05.2009 Head: Prof. Dr.-Ing.habil. S.Fatikow