Improvements in ingestible electronics with the capacity to sense physiologic and pathophysiologic states have transformed the standard of care for patients. Yet despite advances in device development, significant risks associated with solid, non-flexible gastrointestinal transiting systems remain. Here, we disclose an ingestible, flexible piezoelectric device that senses mechanical deformation within the gastric cavity. We demonstrate the capabilities of the sensor in both in vitro and ex vivo simulated gastric models, quantified its key behaviors in the GI tract by using computational modeling, and validated its functionality in awake and ambulating swine. Our piezoelectric devices can safely sense mechanical variations and harvest mechanical energy inside the gastrointestinal tract for diagnosing and treating motility disorders and for monitoring ingestion in bariatric applications.

A piezoelectric sensor manufacturing method according to the present invention comprises the steps of: forming a mold in the form of a sensor array pattern including a plurality of grooves by etching a base substrate; injecting a piezoelectric material in inner grooves among the plurality of grooves and injecting a conductive material in outer grooves; sintering the injected piezoelectric material and conductive material; forming piezoelectric rods and conductive rods by etching the base substrate to protrude the piezoelectric material and the conductive material; forming an insulation layer by filling an insulation material in the base substrate; flattening the insulation layer until the piezoelectric rods and the conductive rods are exposed; forming a first electrode on a first surface of the piezoelectric material and the conductive material; bonding a dummy substrate on the base substrate on which the first electrode is formed; flattening the base substrate until the piezoelectric rods and the conductive rods are exposed; and forming a second electrode on a second surface of the piezoelectric rods and the conductive rods.

A piezoelectric element includes: a piezoelectric part; a first substrate and a second substrate, provided at both sides of the piezoelectric part, respectively; a first electrode layer, located between the first substrate and the piezoelectric part; and a second electrode layer, located between the electrode substrate and the piezoelectric part, wherein a surface of at least one of the first substrate and the second substrate close to the piezoelectric part is provided with a convex portion.

The object of the present invention is to provide a laminated film made of polylactic acids which is not prone to delamination while having excellent piezoelectric properties and a manufacturing method thereof. That is, the present invention is obtained by the stretched laminated film manufactured by a co-extrusion process for use in piezoelectric polymer materials, containing a layer (A) which has poly-L-lactic acid as the primary component and contains an impact modifier in the range of 0.1 to 10 mass % and a layer (B) which has poly-D-lactic acid as the primary component and contains an impact modifier in the range of 0.1 to 10 mass %.

A coating method for producing a function layer on mechanically loaded components or surfaces includes providing or applying a first material layer of a first material or substrate matrix having a mechanical flexibility higher than that of a second material on a substrate constituting the component or the surface, respectively, structuring the first material layer such that the material layer surface of the first material layer, which is opposite to the substrate, obtains a three-dimensionally molded basic structure with projections and recesses, and coating the material layer surface of the first material layer with a second material layer of the second material in such a way that the second material layer adopts substantially the basic structure of the material layer surface with the projections and recesses. Also, surface layer structures can be produced by this method.

This invention provides kilometer-long, endlessly parallel, spontaneously piezoelectric and thermally stable poly(vinylidene fluoride) (PVDF) ribbons using iterative size reduction technique based on thermal fiber drawing method. The PVDF ribbons are thermally stable and conserve the polar phase even after being exposed to heat treatment above the melting point of PVDF. A single PVDF ribbon has an average effective piezoelectric constant as 58.5 pm/V. PVDF ribbons in the invention are promising structures for constructing devices such as highly efficient energy generators, large area pressure sensors, artificial muscle and skin, due to the unique geometry and extended lengths, high polar phase content, high thermal stability and high piezoelectric coefficient.