Sensors and Actuators A-Physical vol:46 issue:1 pages:225-232
This paper describes the design of a piezoresistive, three-axis, hollow micro force/torque sensor. This sensor will be mounted in the Smartpen&unknown;, developed and commercialized by SmartPen N.V. Considering the product's geometrical restrictions, the sensor dimensions are: maximum outer diameter 12 mm; total length 20 mm; minimum inner diameter 7.5 mm. As an additional constraint, the sensor has to be low cost and is to be manufactured in large quantities in an automated production environment. This paper states the role of the force/torque sensor in the Smartpen&unknown;. A method to derive nominal and maximal sensor loading is explained. First, a rough design based on a known sensor concept and calculated using a parametric two-dimensional finite-element model is presented. To calculate detailed characteristics of the sensor, a three-dimensional finite-element model of the sensor is presented. In order to validate the theoretical models used, some preliminary experimental results are also presented.