Innovative tactile sensors

• Piezoresistive Si micro tactile sensors for fast roughness measurements in nozzles and holes with diameters of less than 100 μm (Profilscanner for structures with high aspect ratio) [1]. EMPIR-Project Micro probes
• Microelectro-mechanical systems (MEMS) with small deflections and forces in the nanometer range can be measured [2]. Areas of application: fast surface measurement [3], near-surface measurement of E-modul and hardness [4] and calibration of stiffness of AFM cantilevers [5]
• Recirculated, linear, air-bearing probe system (Lupo) that allows probing forces in the range from 50 µN to 700 µN (tactile reference measuring instrument HRTS [6]).
  In the case of soft materials to determ geometric quantities using tactile methods, special attention must be paid to the probe tip shape and the tactile forces in connection with the material properties [7], [8]. 

Reference standard for the calibration of the probing force, the tip radius and the z-measuring axis

• Si-meander reference spring sensors [9], [10] for calibrating the probing force of coordinate measuring devices, nanoindenters and AFM
• MEMS double-spring sensors for the calibration of the probing force and deflection of stylus instruments, nanoindenters and AFM [11]
• Probe tip test standard for the calibration of the radius and the 2D shape of diamond probe tips of conventional stylus instruments and of special silicon probe tips (Flyer_Stylus tip characterizer_PTB_2017) [12]

Nanoindentation technology with MEMS sensors

• Development of MEMS actuators with capacitive displacement measurement [4]
• Development of a picoindenter for nanoelectromechanical measurement of nanomaterials within the EMPIR project NanoWires "High throughput metrology for nanowire energy harvesting devices" (https://www.ptb.de/empir2020/nanowires/home/)

References  [1] - [16]

The working group calibrated:

• Radial normals with R ≤ 20 μm
• Probing force standard for stylus instruments
• Force-displacement standard for martensity hardeners and nanoindenter
• Cantilever and reference cantilever for scanning force microscopes
• Micro- and nanoforce sensors