Piezoelectric Composite Films Research Articles

Flexible regenerated cellulose/ZnO based piezoelectric composites fabricated via an efficient one-pot method to load high-volume ZnO with assistance of crosslinking

Flexible piezoelectric film has broad application in the energy devices and sensor field. Herein, a highly effective “one-pot method” was proposed to fabricate regenerated cellulose/ZnO piezoelectric composites, in which the preparation of regenerated cellulose (RC), in-suit polymerization of ZnO in RC and its cross linking can be carried out simultaneously. ZnO were in-situ synthesized from Zn2+ reduced by alkali from the dissolve system of cellulose. Simultaneously, the added zinc salt accompanied with acid degradation has promoted the dissolution of cellulose, existing a synergistic effect. In this synthetic process, ECH was used to crosslink cellulose molecules to obtain cross-linked regenerated cellulose (CRC), which enhanced regenerated cellulose framework for more uniform hydroxyl groups as growth sites, thereby further elevate growth content of piezoelectric ZnO distributed uniformly in the composite film. Consequently, the piezoelectric constant (d33) of the developed piezoelectric composite film with excellent tensile strength and flexibility reaches 26.8 ± 6.4 pC N−1. Without external high-voltage polarization, its piezoelectric output open-circuit voltage (VOC) and short-circuit current (ISC) was increased to 6.98 V and 610.27 nA. After polydimethylsiloxane (PDMS) was immersed in the CRC/ZnO aerogel to be CRC/ZnO/PDMS PENG, the piezoelectric output performance was further enlarged to be 10.02 V and 1032.57 nA, respectively, even with a high output stability. It can drive a LED and a small electronic screen, as well as has high sensitivity to pressure excitation, displaying high VOC and ISC up to 17 V and 1300 nA under the trampled state, respectively. The strategy has brought highly efficient assembly and high performance for the piezoelectric nanogenerator (PENG), directly providing a reference to other nanocellulose based PENG.

A wearable nanoscale heart sound sensor based on P(VDF-TrFE)/ZnO/GR and its application in cardiac disease detection.

This paper describes a method for preparing flexible composite piezoelectric nanofilms of P(VDF-TrFE)/ZnO/graphene using a high-voltage electrospinning method. Composition and β-phase content of the piezoelectric composite films were analyzed using X-ray diffraction. The morphology of the composite film fibers was observed through scanning electron microscopy. Finally, the P(VDF-TrFE)/ZnO/graphene composite film was encapsulated in a sandwich-structure heart sound sensor, and a visual heart sound acquisition and classification system was designed using LabVIEW. A heart sound classification model was trained based on a fine K-nearest neighbor classification algorithm to predict whether the collected heart sounds are normal or abnormal. The heart sound detection system designed in this paper can collect heart sound signals in real time and predict whether the heart sounds are normal or abnormal, providing a new solution for the diagnosis of heart diseases.

Supersonically Sprayed Flexible ZnO/PVDF Composite Films with Enhanced Piezoelectricity for Energy Harvesting and Storage

A flexible piezoelectric nanogenerator (PENG) was developed to convert ambient mechanical energy into electrical energy. Highly crystalline template-free zinc oxide (ZnO) microrods were prepared using a wet chemical method at a low temperature. As-synthesized ZnO microrods were blended with polyvinylidene fluoride (PVDF) to prepare a piezoelectric composite film using the supersonic spraying method. A PENG electrode comprising ZnO microrods (0.5 g) produced 15.2 V under a tapping force of 20 N at 5 Hz. In addition, an output current of 32 μA was produced with a maximum power density of 12.5 μW cm–2. The output voltage considering various body movements was investigated to demonstrate the flexibility and durability of the proposed PENG. Furthermore, the supercapacitive properties of ZnO/reduced graphene oxide were studied.

Wearable Piezoelectric Films Based on MWCNT-BaTiO3/PVDF Composites for Energy Harvesting, Sensing, and Localization

Polymer-based lead-free piezoelectric composites provide environmentally friendly and scalable space for energy conversion and structural health monitoring. In this paper, multi-walled carbon nanotubes (MWCNT)-BaTiO3/polyvinylidene fluoride (PVDF) piezoelectric composite films for energy harvesting, sensing, and localization were prepared. The highest β-phase content of 90.21% in PVDF composite nanofibers was achieved owing to the synergistic effect of MWCNT and BaTiO3 nanoparticles. The open-circuit voltage of the flexible piezoelectric nanogenerator based on interdigital electrodes reached 11.4 V at 2 Hz and a bending strain of 4 mm with an optimal power and power density of 8.67 μW and 1.16 μW/cm2, respectively, and can light up to 8 LED lights simultaneously. The output voltage did not decay during 1800 cycles, which met the power and stability requirements of a commercial capacitor. In addition, the prepared piezoelectric sensors exhibited anisotropy and high sensitivity. They had a maximum amplitude sensitivity of 93 dB, which was superior to the reported PVDF-TrFE sensors and suitable for low-frequency signal monitoring in the range of 20–40 kHz. Localization accuracy was greater than 90% in linear and planar localization tests, demonstrating the potential of preparing acoustic emission sensors. These properties facilitate the reduction of the quantity of sensors required to identify the source of damage.

3D-Printed Flexible PVDF-TrFE Composites with Aligned BCZT Nanowires and Interdigital Electrodes for Piezoelectric Nanogenerator Applications

Piezoelectric nanogenerators based on piezoelectric nanocomposites have attracted much interest in recent decades owing to their excellent piezoelectric properties and application in self-powered systems and wearable sensors. As a promising piezoelectric ceramic filler in composite-based generators, one-dimensional (1D) piezoelectric nanowires were filled into a polymer matrix to enhance its dielectric and piezoelectric properties. In this paper, flexible PVDF-TrFE composite films containing highly aligned Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) nanowires (NWs) have been manufactured via a direct-ink writing method. The effect of BCZT NW content on the dielectric, ferroelectric, and piezoelectric properties was investigated using multiphysics modeling and detailed experiments. An optimum composite composition was discovered, and the piezoelectric composite film with 15 wt % BCZT NWs possessed the highest energy harvesting figure of merit of 5.3 × 10–12 m2/N. Interdigital electrodes were combined with the composite to fabricate a patterned piezoelectric nanogenerator, where the piezoelectric nanogenerator can produce an open-circuit output voltage of 17 V, and the maximum output power density could reach 5.6 μW/cm2. This work provides opportunities for the optimization and fabrication of piezoelectric materials for energy-harvesting and sensing applications.

Large-scale fabrication and performance improvement of polyvinylidene fluoride piezoelectric composite films

Sensing applications such as wearable electronics, electronic skin, and soft robotics using flexible piezoelectric films have received extensive attention. In this study, we fabricate large-scale 0–3 type composite films of polyvinylidene fluoride (PVDF)-doped modified lead zirconate titanate (PZT) particles (PZT@UP) through an extrusion-casting process to enhance piezoelectric properties and explain the piezoelectric performance mechanism. The introduction of PZT@UP particles improved the dielectric permittivity of the composite films and promoted the polarization of PVDF, which positively affected the piezoelectric properties of PVDF/PZT@UP films. The composite film with 25 wt% PZT@UP possessed an excellent piezoelectric coefficient (d33) of 29 pC/N, which was 93% higher than that of neat PVDF (15 pC/N). Moreover, the addition of PZT@UP particles effectively inhibited the movement of PVDF molecular chains and improved the mechanical modulus stability of the composite films. The law of electrostrictive effect of the PVDF/PZT@UP composite films is clarified from the aspects of the movement of PVDF molecular chains, the principle of electric field distribution, and the construction of the internal electric field. Further, the similarities and differences between the piezoelectric and electrostrictive mechanisms of the PVDF/PZT@UP composite films are summarized. The extrusion-casting process combined with modified fillers shows promising potential in improving wear and tear of and electricity generation from PVDF-based composite films, leading to a profound impact on the development of large-scale fabrication of piezoelectric sensors.

Improvement of the piezoelectricity of PVDF-HFP by CoFe2O4 nanoparticles

High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ferromagnetic cobalt ferrite (CoFe2O4) (0.00 ​wt% to 0.2 ​wt%) are prepared by a solution casting method accompanied by uniaxial stretching and high electric field poling. The decisive effect of the poling electric field on the power generating capability was confirmed by the experiments. For pure PVDF-HFP films, when the maximum electric field Emax is 120 ​MV/m, the calibrated open circuit voltage reaches 2.93 ​V, which is much higher than those poled at lower electric fields (70 ​MV/m: 1.41 ​V; 90 ​MV/m: 2.11 ​V). Furthermore, the addition of CoFe2O4 also influences the piezoelectricity dramatically. In the samples containing 0.15 ​wt% CoFe2O4, the calibrated open circuit voltage increases to the maximum value of 3.57 ​V. Meanwhile, the relative fraction of the β-phase and the crystallinity degree are 99% and 48%, respectively. The effects of CoFe2O4 nanoparticles on initial crystallization, uniaxial stretching and high electric field poling are investigated by XRD, FTIR and DSC.

Flexible PVDF-TrFE Nanocomposites with Ag-decorated BCZT Heterostructures for Piezoelectric Nanogenerator Applications.

Flexible piezoelectric nanogenerators are playing an important role in delivering power to next-generation wearable electronic devices due to their high-power density and potential to create self-powered sensors for the Internet of Things. Among the range of available piezoelectric materials, poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)-based piezoelectric composites exhibit significant potential for flexible piezoelectric nanogenerator applications. However, the high electric fields that are required for poling cannot be readily applied to polymer composites containing piezoelectric fillers due to the high permittivity contrast between the filler and matrix, which reduces the dielectric strength. In this paper, novel Ag-decorated BCZT heterostructures were synthesized via a photoreduction method, which were introduced at a low level (3 wt %) into the matrix of PVDF-TrFE to fabricate piezoelectric composite films. The effect of Ag nanoparticle loading content on the dielectric, ferroelectric, and piezoelectric properties was investigated in detail, where a maximum piezoelectric energy-harvesting figure of merit of 5.68 × 10-12 m2/N was obtained in a 0.04Ag-BCZT NWs/PVDF-TrFE composite film, where 0.04 represents the concentration of the AgNO3 solution. Modeling showed that an optimum performance was achieved by tailoring the fraction and distribution of the conductive silver nanoparticles to achieve a careful balance between generating electric field concentrations to increase the level of polarization, while not degrading the dielectric strength. This work therefore provides a strategy for the design and manufacture of highly polarized piezoelectric composite films for piezoelectric nanogenerator applications.

Bio-compatible piezoelectric material based wearable pressure sensor for smart textiles

With the rapid advancement of flexible wearable technology, bio-compatible textile piezoelectric pressure sensors are a promising candidates for next-generation sensing platforms to monitor human health. Smart textiles can be easily incorporated into our daily wear clothing in a breathable and conformable manner. In this study, a novel structural hierarchy consisting of a piezoelectric composite film Glycine–Chitosan (GC) sandwiched between two Zinc Oxide (ZnO) nanorods patterned conductive textile electrodes was developed. A low temperature hydrothermal method was used to grow ZnO nanorods directly on the conductive fabric, and a simple solvent casting technique was employed to form a GC film. Scanning electron microscopy and x-ray diffraction analyses were performed to investigate the growth of the bio-compatible piezoelectric materials. Under periodic deformation, the fabricated sensor exhibited a good piezoelectric response over a wide range of sensing pressures. The use of non-toxic, bio-compatible piezoelectric materials in the development of textile pressure sensors paves the way for the development of eco-friendly wearables.

Synthesis of a nitrogen doped reduced graphene oxide based ceramic polymer composite nanofiber film for wearable device applications

In this study, piezoelectric composite nanofiber films were fabricated by introducing nitrogen-doped-reduced-graphene-oxide as a conductive material to a P(VDF-TrFE) polymer and a BiScO3–PbTiO3 ceramic composite employing an electrospinning process. Nitrogen was doped/substituted into rGO to remove or compensate defects formed during the reduction process. Electro-spinning process was employed to extract piezoelectric composite nanofiber films under self-poling condition. Interdigital electrodes was employed to make planner type energy harvesters to collect electro-mechanical energy applied to the flexible energy harvester. From the piezoelectric composite with interdigital electrode, the effective dielectric permittivity extracted from the conformal mapping method. By introducing BS–PT ceramics and N-rGO conductors to the P(VDF-TrFE) piezoelectric composite nanofiber films, the effective dielectric permittivity was improved from 8.2 to 15.5. This improved effective dielectric constant probably come from the increased electric flux density due to the increased conductivity. Fabricated interdigital electrode using this thin composite nanofiber film was designed and tested for wearable device applications. An external mechanical force of 350 N was applied to the composite nanofiber-based energy harvester with interdigital electrodes at a rate of 0.6 Hz, the peak voltage and current were 13 V and 1.25 μA, respectively. By optimizing the device fabrication, the open-circuit voltage, stored voltage, and generated output power obtained were 12.4 V, 3.78 V, and 6.3 μW, respectively.

Piezoelectric Properties of 0-3 Composite Films Based on Novel Molecular Piezoelectric Material (ATHP)2PbBr4.

Since their discovery, ferroelectric materials have shown excellent dielectric responses, pyroelectricity, piezoelectricity, electro-optical effects, nonlinear optical effects, etc. They are a class of functional materials with broad application prospects. Traditional pure inorganic piezoelectric materials have better piezoelectricity but higher rigidity; pure organic piezoelectric materials have better flexibility but havetoo small a piezoelectric coefficient. The material composite, on the other hand, can combine the advantages of both, so that it has both flexibility and a high piezoelectric coefficient. In this paper, a new molecular piezoelectric material (C5H11NO)2PbBr4 with a high Curie temperature Tc and a large piezoelectric voltage constant g33, referred to as (ATHP)2PbBr4, was used to prepare a 0-3 type piezoelectric composite film by compounding with an organic polymer material polyvinylidene fluoride (PVDF), and its ferroelectricity was investigated. The results show that the 0-3 type (ATHP)2PbBr4 piezoelectric composite film has good ferroelectricity and piezoelectricity, and the calculated piezoelectric voltage constant g33 after polarization is about 358.6 × 10−3 Vm/N, which is higher than that of PVDF material, and is important for the fabrication of high-performance piezoelectric sensors.

Incorporation of ZnO encapsulated MoS2 to fabricate flexible piezoelectric nanogenerator and sensor

Polymer based piezoelectric composite has attracted much attention in recent years due to its applicability in the manufacture of piezoelectric nanogenerators and sensors, high piezoelectric performance, high flexibility and easily shaping properties. In this work, ZnO with good piezoelectric properties was grown on the exfoliated MoS2 nanosheets by employing in situ polymerization, which was then incorporated in PVDF to prepare PVDF/MoS2@ZnO piezoelectric composite film. The effect of various contents of ZnO on its structure and properties was emphatically discussed, as well as the mechanical energy collection and sensing performance. The results show that ZnO has been deposited on the surface of MoS2 nanosheet to form heterostructure (MoS2@ZnO), as well as that the MoS2@ZnO can effectively promote the transformation from α phase to β phase in PVDF, by which the content of β phase can be increased from 6.2 ± 2.5 % to 54.3 ± 2.7 %. It also exhibits excellent mechanical performance and flexibility with the tensile strengthen of 37.64 ± 5.12 MPa and elongation at break of 9.77 ± 1.57 %. The longitudinal piezoelectric constant (d33) of the composite film reached a maximum value of 31 ± 4 pC·N-1. The open-circuit voltage (VOC) and short-circuit current (ISC) of PVDF/MoS2@ZnO piezoelectric composite film reach as high as 6.22 V and 528 nA under the acting force of 100 KPa, respectively. It can charge a 1.0 μF commercial capacitor to 1.81 V in 400 s. Finally, a flexible piezoelectric sensor was fabricated to collect the pressure signals induced from human body movement (the bending of fingers, wrists and elbow joints), presenting excellent sensitive piezoelectric response with the VOC of about 0.41 V, 0.22 V and 0.32 V, respectively. The found performance indicates its feasibility for the application in wearable intelligent devices.

Piezo-phototronic effect in highly stable lead-free double perovskite Cs2SnI6-PVDF nanocomposite: Possibility for strain modulated optical sensor

Metal halide perovskites (MHPs) are highly emerging materials for their applications in the field of photovoltaics and optoelectronics. However, beyond these applications, the MHPs have been proven to be excellent candidates for the fabrication of self-powered nanogenerators on their own or in conjunction with piezoelectric polymers such as poly(vinylidene-fluoride) (PVDF). More so, lead-free MHPs are the need of hour, which opens up the possibility of a sustainable future. Additionally, in piezoelectric composite films containing MHP, it is possible to utilize the coupling of photoexcitation, semiconducting and piezoelectric properties, which leads to the piezo-phototronic effect. Here, we report the fabrication of Cs2SnI6-PVDF (CSIP) composite, where the synthesis of Cs2SnI6 nanoparticles was realized in an in-situ approach. Notably, the Cs2SnI6 nanoparticles nucleates 100% electroactive β- and γ-phases in PVDF which gives rise to the intrinsic piezoelectric nature of the lead free composite film. Furthermore, to decipher the interfacial interaction between Cs2SnI6 and PVDF first principle DFT study was performed which unravels the non-bonding interaction between the Cs2SnI6 and PVDF. The piezo-phototronic effect was successfully realized in the CSIP film indicating its promising use in the piezotronics sensor. Moreover, the CSIP films were utilized as a piezoelectric nanogenerator, which shows superior piezoelectric output voltage of 9 V and current of 5 μA. It can also be utilized in human physiological signal monitoring, as well as a pressure sensor. Hence, the combined properties of semiconducting, photoexcitation and piezoelectricity in the CSIP films can be utilized in both mechanical energy harvesting and piezotronics sensing applications.

A plantar wearable pressure sensor based on hybrid lead zirconate-titanate/microfibrillated cellulose piezoelectric composite films for human health monitoring.

Flexible and wearable electronic sensors hold great promise for improving the quality of life, especially in the field of healthcare monitoring, owing to their low cost, flexibility, high electromechanical coupling performance, high sensitivity, and biocompatibility. To achieve high piezoelectric performance similar to that of rigid materials while satisfying the flexible requirements for wearable sensors, we propose novel hybrid films based on lead zirconate titanate powder and microfibrillated cellulose (PZT/MFC) for plantar pressure measurements. The flexible films made using the polarization process are tested. It was found that the maximum piezoelectric coefficient was 31 pC N-1 and the maximum tensile force of the flexible films was 26 N. A wide range of bending angles between 15° and 180° proves the flexibility capability of the films. In addition, the charge density shows a proportional relation with the applied mechanical force, and it could sense stress of 1 kPa. Finally, plantar pressure sensors are arranged and packaged with a film array followed by connection with the detection module. Then, the pressure curves of each point on the plantar are obtained. Through analysis of the curve, several parameters of human body motions that are important in the rehabilitation of diabetic patients and the detection of sports injury can be performed, including stride frequency, length and speed. Overall, the proposed PZT/MFC wearable plantar pressure sensor has broad application prospects in the field of sports injury detection and medical rehabilitation training.

Noninvasive manipulation of cell adhesion for cell harvesting with piezoelectric composite film

Cell sheet harvesting has recently emerged as a promising strategy for scaffold-free cell transplantation and tissue engineering. It is critical to achieve the disconnection between cell and its adherent support while maintaining the availability of cell sheet. Hence, the regulation of cell adhesion behavior often becomes the primary consideration for designing biomaterials used for cell sheet harvesting. The stimuli-responsive biomaterials can rationally modulate cell behaviors, especially adhesion performance. However, modulation of cell adhesion through noninvasive and highly efficient method is still greatly needed. Herein, a noninvasive low-intensity ultrasound-mediated cell harvesting is demonstrated based on the piezoelectric effect of polyvinylidene fluoride (PVDF)/barium titanate (BaTiO3, BTO) composite film with superior electromechanical conversion ability. We found that the piezoelectric effect triggered by ultrasound (US) can modulate the absorption and secondary structure of adhesive protein fibronectin (FN) on the composite film, which further influenced cell adhesion force to finally obtain free-standing cell sheets. The detached cell sheets with accurate comtrol retained their viability and excellent proliferative capability. These findings highlight the ability of the piezoelectric biomaterials for cell sheet engineering to serve as a noninvasive and accurately controllable platform via regulating surface protein adsorption and conformation, which indicates great application prospect of this piezoelectricity-based cell harvesting method in regenerative medicine.

LiTaO3-Based Flexible Piezoelectric Nanogenerators for Mechanical Energy Harvesting.

Mechanical energy is one of the freely available green energy sources that could be harvested to meet the small-scale energy demand. Piezoelectric nanogenerators can be used to harvest the biomechanical energy that is available in everyday human life and power various portable electronics. Herein, a ferroelectric material, i.e., lithium tantalate (LiTaO3), was synthesized and used to fabricate a flexible piezoelectric nanogenerator (FPNG). Generally, ferroelectric materials display a strong electrostatic dipole moment and high piezoelectric coefficient, thus resulting in enhanced electrical performance. First, LiTaO3 nanoparticles were synthesized and loaded into poly(vinylidene difluoride) (PVDF) to form a piezoelectric film and then, the piezoelectric composite film was sandwiched between two aluminum electrodes to fabricate an FPNG. The effect of the electrical performance of FPNG as a function of the concentration of LiTaO3 loaded into PVDF was systematically investigated and optimized. The 2.5 wt % FPNG exhibited open-circuit voltage, short-circuit current, and power density values of ∼18 V, ∼1.2 μA, and ∼25 mW/m2, respectively. Furthermore, the FPNG revealed good electrical stability and mechanical durability. Finally, the FPNG was employed as a weight sensor to harvest various biomechanical energies and operate low-power- electronics.

A Micro-Power Generator Based on Two Piezoelectric MFC Films

In order to realize the collection of micro or small vibration energy, a micro-power generator based on two piezoelectric Macro Fiber Composite (MFC) films is proposed. The piezoelectric generator consists of a double piezoelectric MFCs type vibrator and a displacement amplifying mechanism, which can achieve the output of high energy density. The design process of this kind of piezoelectric generator is presented. Based on LabVIEW platform and NI Data Acquisition (DAQ) card, the output voltage acquisition system of the generator is built, and the output voltage and power are collected and calculated. Experimental results show that the maximum output power is 6.2 mW under transient excitation. Under continuous excitation with a load resistance of 10 kΩ and an excitation frequency of 26 Hz, the maximum output of the generator is up to 11.9 mW. The research results lay a foundation for the application of the proposed micro-power piezoelectric generator.

Flexible lead-free NBT-BT/PVDF composite films by hot pressing for low-energy harvesting and storage

The idea of this work is finding the way to efficiently and safely use mechanical energy released in small quantities around us to power up small-scale electronic devices used in everyday life. To this purpose, flexible lead-free piezoelectric composite films were prepared by hot pressing. Different amounts (30, 35 and 40 vol%) of lead-free piezoelectric material bismuth sodium titanate-barium titanate were embedded in the matrix of polyvinylidene fluoride under carefully optimized conditions of temperature and pressure, obtaining flexible films with quite homogeneous distribution of piezo-active filler. ATR-FTIR analysis revealed that hot pressing the flexible films caused a transformation of electro-inactive PVDF α-phase into electro-active β and γ phases. Dielectric measurements showed an increase of the permittivity up to 80 with the active phase increasing. Anelastic measurements showed that the elastic modulus increases as well with the fraction of active ceramic phase. Lastly, obtained flexible polymer-composites demonstrated notable properties both for energy storage and energy harvesting application, showing up to 74% of energy storage efficiency and, from testing of the force impact, up to 9 V and ~ 80 μW of output voltage and power.

Piezoelectricity of PVDF composite film doped with dopamine coated nano-TiO2

In this work, dopamine (DA) coated nano-TiO2 (DA@TiO2) modified polyvinylidene fluoride (PVDF) piezoelectric composite films (DA@TiO2/PVDF) with a high β-phase content are successfully fabricated by solvothermal method. The β-phase content of the DA2.0@TiO2/PVDF reaches 84.33%. Furthermore, DA2.0@TiO2/PVDF has the highest crystallinity (Xc) and melting enthalpy (ΔH). Due to synergistic effect between DA and TiO2, the piezoelectric coefficients (d33) and remnant polarization (Pr) of DA2.0@TiO2/PVDF composite films increase by up to 163% and 278% than that of the pure PVDF film, respectively. This work provides a new method to present promise in broadening nanometer preparation technology and improving performance of piezoelectric composites, and contributes to the study on new curved panel energy harvesters for aeroelastic vibration.

Ultrasound-driven electrical stimulation of peripheral nerves based on implantable piezoelectric thin film nanogenerators

Electrical stimulation of peripheral nerves is a powerful tool in neuroprosthesis and bioelectronic medicines to treat diverse clinical conditions. To achieve minimally invasive bioelectrical interfaces, the new generation of soft implantable neurostimulators with programmable electrical-stimulation functionality is highly demanded, but it remains a big challenge. Owing to the advantages of ultrasound in biomedical applications, such as deep tissue penetration and excellent clinical safety, we explore directly electrical stimulation of peripheral nerves with soft piezoelectric thin film nanogenerator which can be remotely driven by programmable ultrasound pulses. An ultrasound-active thin film nanogenerator with superior output performance was developed on basis of piezoelectric composite thin films containing 0.5Ba(Zr 0.2 Ti 0.8 )O 3 -0.5(Ba 0.7 Ca 0.3 )TiO 3 (BZT-BCT) nanowires and polyvinylidene fluoride (PVDF) polymer. The piezoelectric thin film nanogenerators without accessory rectifiers can directly serve as neurostimulators, and the electrical pulses generated by the implantable piezoelectric thin film nanogenerator can be programmed by remote ultrasound excitation with adjustable input power and waveform. With sciatic nerves of rats as a model, the directly electrical neurostimulation was successfully achieved by subcutaneously implanted piezoelectric thin film nanogenerators with thickness of around 30 µm, and the stimuli controllability was systematically investigated with varied ultrasound parameters, including acoustic pressure, pulse width and pulse interval. Our ultrasound-driven electrical stimulation of peripheral nerves with ultrasound-active implantable thin film nanogenerators demonstrated a novel strategy to construct a programmable battery-free neurostimulator using soft and implantable energy devices which can be real-time-responsive to programmable external energy sources. • Electrical stimulation of peripheral nerves with soft implantable PENG which can be remotely driven by ultrasound. • The ultrasound-active soft PENG composed of 10 µm thick piezoelectric composite has superior electrical output performance. • This battery-free neurostimulator can be programmed by acoustic pressure, pulse width and pulse interval.