Compliance detection becomes very essential inminimally
invasive surgery (MIS). It can help in detection of cancerous
lumps and/or for deciding on tissue healthiness. In this paper, a
micromachined piezoresistive tactile sensor, with two serpentine
springs and 500-μm cubic mesas, has been designed for detecting
the compliance of soft tissue independent of the applied distance
between the sensor and the tissue. The measuring range of the
sensor is chosen to be associated with the soft-tissue properties.
The sensor parameters are optimized to give high sensitivity and
linearity of the sensor output. The design is simulated using
ANSYS for checking the sensor performance. Then, the sensor is
fabricated and tested by three types of specimens, namely, specimen
chips with known stiffness, silicone rubber specimens, and
chicken organ specimens (leg and heart). For the specimen chips
and silicone rubber specimens, the sensor distinguished between
different stiffnesses independent of the applied displacement in the
range of 50–200 μm. The sensor measured Young’s modulus up to
808 kPa with an average error of±7.25%. For the chicken leg and
heart, the sensor distinguished between them under the applied
displacement from 100 to 200 μm, and they were calculated as
12 ± 1 kPa and 81 ± 8 kPa, respectively.