3 research outputs found
Soft, Transparent, Electronic Skin for Distributed and Multiple Pressure Sensing
In this paper we present a new optical, flexible pressure sensor that can be applied as smart skin to a robot or to consumer electronic devices. We describe a mechano-optical transduction principle that can allow the encoding of information related to an externally applied mechanical stimulus, e.g., contact, pressure and shape of contact. The physical embodiment that we present in this work is an electronic skin consisting of eight infrared emitters and eight photo-detectors coupled together and embedded in a planar PDMS waveguide of 5.5 cm diameter. When a contact occurs on the sensing area, the optical signals reaching the peripheral detectors experience a loss because of the Frustrated Total Internal Reflection and deformation of the material. The light signal is converted to electrical signal through an electronic system and a reconstruction algorithm running on a computer reconstructs the pressure map. Pilot experiments are performed to validate the tactile sensing principle by applying external pressures up to 160 kPa. Moreover, the capabilities of the electronic skin to detect contact pressure at multiple subsequent positions, as well as its function on curved surfaces, are validated. A weight sensitivity of 0.193 gr−1 was recorded, thus making the electronic skin suitable to detect pressures in the order of few grams
Design, manufacturing and characterisation of a wireless flexible pressure sensor system for the monitoring of the gastro-intestinal tract
Ingestible motility capsule (IMC) endoscopy holds a strong potential in providing
advanced diagnostic capabilities within the small intestine with higher patient tolerance
for pathologies such as irritable bowel syndrome, gastroparesis and chronic abdominal
amongst others. Currently state-of-the art IMCs are limited by the use of obstructive off-the-shelf sensing modules that are unable to provide multi-site tactile monitoring of the
Gastro-Intestinal tract.
In this work a novel 12 mm in diameter by 30 mm in length IMC is presented that utilises
custom-built flexible, thin-film, biocompatible, wireless and highly sensitive tactile
pressure sensors arrays functionalising the capsule shell. The 150 μm thick,
microstructured, PDMS flexible passive pressure sensors are wirelessly powered and
interrogated, and are capable of detecting pressure values ranging from 0.1 kPa up to 30
kPa with a 0.1 kPa resolution. A novel bottom-up wafer-scale microfabrication process
is presented which enables the development of these ultra-dense, self-aligned, scalable
and uniquely addressable flexible wireless sensors with high yield (>80%). This thesis
also presents an innovative metallisation microfabrication process on soft-elastomeric
substrates capable to withstand without failure of the tracks 180o
bending, folding and
iterative deformation such as to allow conformable mapping of these sensors. A custom-built and low-cost reflectometer system was also designed, built and tested within the
capsule that can provide a fast (100 ms) and accurate extraction (±0.1 kPa) of their
response. In vitro and in vivo characterisation of the developed IMC device is also
presented, facilitated respectively via the use of a biomimetic phantom gut and via live
porcine subjects. The capsule device was found to successfully capture respiration, low-amplitude and peristaltic motility of the GI tract from multiple sites of the capsule.UK Engineering & Physical Sciences Research Council (EPSRC) through the Programme Grant Sonopill
(EP/K034537/2)James Watt Scholarshi