Design analysis and fabrication of a mobile energy harvesting device to scavenge bio-kinetic energy.

The increasing prevalence of low power consumption electronics brings greater potential to mobile energy harvesting devices as a possible power source. The main contribution of this thesis is the study of a new piezoelectric energy harvesting device, called the piezoelectric flex transducer (PFT), which is capable of working at non- resonant and low frequencies to harvest bio-kinetic energy of a human walking. The PFT consists of a piezoelectric element sandwiched between substrate layers and metal endcaps, the endcaps are specifically designed to amplify the axial force load on the piezoelectric element, instead of conventional designs of piezoelectric energy harvesters that focus on utilising resonant frequency in order to increase power harvested. This thesis presents the analyses, design, prototyping and characterisation of the PFT using a coupled piezoelectric-circuit finite element model (CPC-FEM) to show the energy harvesting capability of the proposed and developed novel device to harvest bio-kinetic energy. Prior to the study of the new PFT, an initial focus was given to a traditional Cymbal device to investigate its potential as a bio-kinetic energy harvesting device. To gain an understanding, effects of geometrical parameters and material properties of the device on its energy harvesting capability were studied and in doing so issues and problems were identified with the traditional Cymbal device for use as a bio-kinetic energy harvesting device. Its structural materials were not able to withstand higher than a 50N applied load and it was proposed that a small adhesion area connection in a fundamental part of the structure may have been at high risk of delamination. In order to study these, the CPC-FEM model was developed using the commercial software of ANSYS and validated by experimental methods. Later, based on a modelling and experimental study, a novel PFT was proposed and implemented to overcome the issues and problems of the traditional Cymbal device. For this initial study, the Cymbal was analysed by studying how key dimensional parameters affect the energy harvesting performance of the Cymbal. In addition to this, how piezoelectric material properties affect the energy harvesting performance were studied using the developed CPC-FEM model through comparisons of different piezoelectric materials and their electrical performances to aid with selecting high power producing materials for the final PFT design. It was found that (1) d₃₁ is a more dominant material property over other material properties for higher power output, (2) Figure of Merit (FOM) was more linear related to the power output than either the k₃₁ or the d₃₁, and (3) εᵀ r₃₃ had some role when the materials have an identical d₃₁; a lower ε ᵀ₃₃ was preferred. A combined FOM with d₃₁ parameters is recommended for selection of piezoelectric material for a higher power outputs. The design of the new PFT is partly based on the traditional Cymbal however, the new PFT has more potential for withstanding higher forces due to an addition of substrate layers that reduced delamination risks. Using a similar approach to designing the traditional Cymbal, the new PFT was designed and tested with force frequencies of less than 5Hz and forces of up to 1kN. In the design process, the validated CPC-FEM was used 1) to analyse then utilise correlations between geometric parameters and power outputs, and 2) to ensure structural integrity by monitoring mechanical stress in the PFT. The PFT was retrofitted into a shoe and the harvested power was used to power an in-house developed wireless sensor module whilst the subject with a body weight of 760N was wearing the shoe and ran at 3.1mph (equivalent to 1.4Hz on the shoe), the PFT produced an average maximum power of 2.5mW over 2MΩ load and the power produced is able to power the wireless module approximately every 10 seconds.Engineering and Physical Sciences (EPSRC)PhD in the School of Applied Science

Resonant ultrasonic bone penetrating needles

Bone biopsy is an invasive clinical procedure where a bone sample is recovered for analysis during the diagnosis of a medical condition. The procedure is performed while the patient is under either local or general anaesthesia as the patient can experience significant discomfort and possibly large haematoma due to the large axial and rotational forces applied through the needle to penetrate bone. It is well documented that power ultrasonic surgical devices offer advantages of low cutting force, high accuracy and preservation of soft tissues. This thesis details a study of the design, analysis and evaluation of a class of novel power ultrasonic needles for bone penetration, particularly biopsy. Micrometric vibrations generated at the distal tip of a full-wavelength resonant ultrasonic device are used to penetrate the bone. Both ultrasonic longitudinal (L) and longitudinal-torsional (L-T) coupled vibration have proven successful in several applications including ultrasonic surgical devices. Interest in ultrasonic bone cutting has grown since it was first introduced commercially as Piezosurgery in the 1990s. More recent studies have focused on precision cutting of bone, reducing the risk of damage to surrounding delicate tissues in comparison with manual and other powered instruments. Finite element analysis (FEA) is used to design full wavelength ultrasonic needle devices, where the geometry of the device is systematically modified to deter modal coupling by monitoring the frequency spacing between the longitudinal mode of interest and the neighbouring parasitic modes. FEA is further exploited to predict the achievable torsional displacement in a composite mode device tuned to vibrate in a longitudinal-torsional motion through degeneration of the longitudinal motion. While the L-mode device requires the operator to apply a slow backward and forward rotation and a small forward force, to maintain a forward motion and avoid imprinting, a L-T motion at the tip device could avoid this, simplifying the procedure, increasing precision and resulting in a cylindrical, less damaged hole surface. The dynamic behaviours predicted by FEA are validated through experimental modal analysis (EMA) demonstrating the effectiveness of FEA for the design of these devices. EMA is performed by exciting the ultrasonic needle device with a low power random excitation over a predetermined frequency range and measuring the vibration response using a 3D laser Doppler vibrometer (LDV) across a grid of points on the surface of the device. Harmonic analysis was used to investigate the behaviour of the devices at high excitation levels to capture the inherent nonlinearity of the tuned device. The response is captured using bi-directional frequency sweeps across the tuned mode of interest at increasing excitation levels. Ultrasonic surgical instruments typically require to be driven at high excitation levels to generate sufficient vibration amplitude to cut or aspirate tissue or seal vessels. The nonlinearities of the instrument and load presented by the target tissue result in resonance frequency shift, variation in the electric impedance and instability in the vibrational response which can negatively affect the efficacy of the instrument. A resonance tracking system was developed to monitor the voltage and current and adjust the frequency in real time to compensate for the frequency shift. Additional functionality was incorporated to allow modifications to the excitation signal shape and to enable power modulation techniques to be tested in a study of their effects on the rate of progression of the device in its target tissue. Prototype ultrasonic needle devices were evaluated in penetration tests conducted in bone mimic materials and animal bones. The devices recovered trabecular bone from the metaphysis of an ovine femur, and the biopsy samples were architecturally comparable to samples extracted using a trephine biopsy needle. The resonant needle device extracted a cortical bone sample from the central diaphysis, which is the strongest part of the bone, and the biopsy was of superior quality to the sample recovered by a trephine bone biopsy needle. The biopsy sample extracted by the resonant needle was architecturally uniform and cylindrical with an absence of chipping on the surface, suggesting that the biopsy was extracted with precision and control. To penetrate with the L mode device, the operator had to apply a slow backward and forward rotation and the small forward force, to maintain a forward motion. The rotation had to avoid imprinting of the needle tip in the bone, which otherwise resulted in the device stalling. However the L-T mode device, realised by incorporating helical cuts along the axial length, could penetrate the same animal bone sample only requiring the small forward force, hence simplifying the procedure for the operator. The L-T device also provided increased precision, resulting in a cylindrical, less damaged hole surface. Finally, a case study related to skull-based surgery is presented. The petrous apex is a pyramidal shaped structure at the anterior superior portion of the temporal bone and can be the location of tumours, cysts and lesions requiring diagnostic investigation. The petrous apex is challenging to access due to its medial location in the skull base and closeness to important neurovascular structures. An extended surgical approach removes the subject but is associated with morbidity and hence a minimally invasive procedure to access this site to retrieve a biopsy provides a valuable test case for the ultrasonic needle. Guided by the expertise and experience of an ear, nose and throat surgeon, the ultrasonic needle devices were modified and demonstrated in lab-based studies as a new technology for this bone penetration procedure

Nanostructured piezoelectric materials for the design and development of self-sensing composite materials and energy harvesting devices

The work activities reported in this PhD thesis regard the functionalization of composite materials and the realization of energy harvesting devices by using nanostructured piezoelectric materials, which can be integrated in the composite without affecting its mechanical properties. The self-sensing composite materials were fabricated by interleaving between the plies of the laminate the piezoelectric elements. The problem of negatively impacting on the mechanical properties of the hosting structure was addressed by shaping the piezoelectric materials in appropriate ways. In the case of polymeric piezoelectric materials, the electrospinning technique allowed to produce highly-porous nanofibrous membranes which can be immerged in the hosting matrix without inducing delamination risk. The flexibility of the polymers was exploited also for the production of flexible tactile sensors. The sensing performances of the specimens were evaluated also in terms of lifetime with fatigue tests. In the case of ceramic piezo-materials, the production and the interleaving of nanometric piezoelectric powder limitedly affected the impact resistance of the laminate, which showed enhanced sensing properties. In addition to this, a model was proposed to predict the piezoelectric response of the self-sensing composite materials as function of the amount of the piezo-phase within the laminate and to adapt its sensing functionalities also for quasi-static loads. Indeed, one final application of the work was to integrate the piezoelectric nanofibers in the sole of a prosthetic foot in order to detect the walking cycle, which has a period in the order of 1 second. In the end, the energy harvesting capabilities of the piezoelectric materials were investigated, with the aim to design wearable devices able to collect energy from the environment and from the body movements. The research activities focused both on the power transfer capability to an external load and the charging of an energy storage unit, like, e.g., a supercapacitor

Leading the Charge in Bone Healing: Design of Compliant Layer Adaptive Composite Stacks for Electrical Stimulation in Orthopedic Implants

The overall aim of this research is to develop a robust, adaptable piezoelectric composite load-bearing biomaterial that when integrated with current implants, can harvest human motion and subsequently deliver electrical stimulation to trigger the natural bone healing and remodeling process. Building on the preclinical success of a stacked piezocomposite spinal fusion implant, compliant layer adaptive composite stacks (CLACS) were designed as a scalable biomaterial to increase efficiency of power generation while maintaining mechanical integrity under fatigue loading seen in orthopedic implants. Energy harvesting with piezoelectric material is challenging at low frequencies due to material properties that limit total power generation at these frequencies and brittle mechanical properties. Stacked generators increase power generation at lower voltage levels and resistances, but are not efficient at low frequencies seen in human motion. CLACS integrates compliant layers between the stiff piezoelectric elements within a stack, capitalizing on the benefits of stacked piezoelectric generators, while decreasing stiffness and increasing strain to amplify power generation. The first study evaluated CLACS under compressive loads, demonstrating the power amplification effect as the thickness of the compliant layer increases. The second study characterized the effect of poling direction of piezoelectric discs within a CLACS structure under multiaxial loads, demonstrating an additional increase in power generation when mixed poling directions are used to create mixed-mode CLACS. The final study compared the fatigue performance and power generation capability of three commercially fabricated piezoelectric stack generators with and without CLACS technology in modified implant assemblies. All configurations produced sufficient power to stimulate bone growth, and maintained mechanical strength throughout a high load, low cycle fatigue analysis, thus validating feasibility for use in orthopedic implants. The presented work in this dissertation provides a robust experimental understanding of CLACS and a characterization of how piezoelectric properties and composite structures can be tailored within the CLACS structure to efficiently generate power in low frequency, low impedance applications. The main motivation of this work was to develop a thorough understanding of CLACS behavior for implementation into medical implants to deliver therapeutic electrical stimulation and accelerate rate of bone growth, helping patients completely heal faster. However, the ability to tune composite stiffness by changing compliant material properties, type of piezoelectric material and poling direction, or volume fractions could benefit the energy harvesting potential in fields ranging from civil infrastructure to wind energy, to wearables and athletic equipment

Development and characterization of sensors fabricated from polymer based magnetoelectric nanocomposites

Tese de Doutoramento em Engenharia Electrónica e de ComputadoresSensors are increasingly used in many applications areas, integrated in structures, industrial machinery, or in the environment, contributing to improve the society level of well-being. It is expected that sensorization will play on of the most relevant roles in the fourth industrial revolution, and allow, together with mechanization and informatization, a full automation. Particularly, magnetic sensors allow measurements, without physical contact, of parameters such as direction, presence, rotation, angle, or current, in addition to magnetic field. In this way, for most applications, such sensors offer a safe, noninvasive and non-destructive measurement, as well as provide a reliable and almost maintenance-free technology. Industry demands for smaller, cheaper and low-powered magnetic sensors, motivating the exploration of new materials and different technologies, such as polymerbased magnetoelectric (ME) composites. These composites are flexible, versatile, lightweight, low cost, easy to model in complicated shapes, and typically involve a lowtemperature fabrication process, being in this way, a solution for innovative magnetic sensor device applications. Therefore, the main objective of this thesis is the development of polymer-based ME sensors to be incorporated into technological devices. Thus, the ME effect is increasingly being considered an attractive alternative for magnetic field and current sensing, being able to sense static and dynamic magnetic fields. In order to obtain a wide-range ME response, a nanocomposite of Tb0.3Dy0.7Fe1.92 (Terfenol-D)/CoFe2O4/poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) was produced and their morphological, piezoelectric, magnetic and magnetoelectric properties investigated. The obtained composites reveals a high piezoelectric response (≈-18 pC∙N- 1) that is independent of the weight ratio between the fillers. In turn, the magnetic properties of the composites are influenced by the composite composition. It was found that the magnetization saturation values decrease with increasing CoFe2O4 content (from 18.5 to 13.3 emu∙g-1) while the magnetization and coercive field values increase (from 3.7 to 5.5 emu∙g-1 and from 355.7 to 1225.2 Oe, respectively) with increasing CoFe2O4 content. Additionally, the films show a wide-range dual-peak ME response at room temperature with the ME coefficient increasing with increasing weight content of Terfenol-D, from 18.6 mV∙cm-1∙Oe-1 to 42.3 mV∙cm-1∙Oe-1. The anisotropic ME effect on a Fe61.6Co16.4Si10.8B11.2 (FCSB)/poly(vinylidene fluoride) (PVDF)/FCSB laminate composite has been used for the development of a magnetic field sensor able to detect both magnitude and direction of ac and dc magnetic fields. The accuracy (99% for both ac and dc sensors), linearity (92% for the dc sensor and 99% for the ac sensor), sensitivity (15 and 1400 mV∙Oe-1 for the dc and ac fields, respectively), and reproducibility (99% for both sensors) indicate the suitability of the sensor for applications. A dc magnetic field sensor based on a PVDF/Metglas composite and the corresponding readout electronic circuits for processing the output ME voltage were developed. The ME sensing composite presents an electromechanical resonance frequency close to 25.4 kHz, a linear response (r2=0.997) in the 0–2 Oe dc magnetic field range, and a maximum output voltage of 112 mV (ME voltage coefficient α33 of ≈30 V∙cm-1∙Oe-1). By incorporating a charge amplifier, an ac–rms converter and a microcontroller with an on chip analog-to-digital converter (ADC), the ME voltage response is not distorted, the linearity is maintained, and the ME output voltage increases to 3.3 V (α33effective=1000 V∙cm-1∙Oe-1). The sensing device, including the readout electronics, has a maximum drift of 0.12 Oe with an average total drift of 0.04 Oe, a sensitivity of 1.5 V∙Oe-1 (15 kV∙T-1), and a 70 nT resolution. Such properties allied to the accurate measurement of the dc magnetic field in the 0–2 Oe range makes this polymerbased device very attractive for applications, such as Earth magnetic field sensing, digital compasses, navigation, and magnetic field anomaly detectors. A dc current sensor device based on a ME PVDF/Metglas composite, a solenoid, and the corresponding electronic instrumentation were developed. The ME sample exhibits a maximum α33 of 34.48V∙cm-1∙Oe-1, a linear response (r2=0.998) and a sensitivity of 6.7 mV∙A-1. With the incorporation of a charge amplifier, a precision ac/dc converter and a microcontroller, the linearity is maintained (r2=0.997), the ME output voltage increases to a maximum of 2320 mV and the sensitivity is increased to 476.5 mV∙A-1. Such features indicate that the fabricated ME sensing device is suitable to be used in non-contact electric current measurement, motor operational status checking, and condition monitoring of rechargeable batteries, among others. In this way, polymer-based ME composites proved to be suitable for magnetic field and current sensor applications.Os sensores estão a ser cada vez mais utilizados em diversas áreas, integrados em estruturas, máquinas industriais ou projetos ambientais, contribuindo para melhorar o nível de bem-estar e eficiência da nossa sociedade. Espera-se que a “sensorização” contribua decisivamente para a quarta revolução industrial, e que permita, em conjunto com a mecanização e a informatização, uma completa automação. Em particular, os sensores magnéticos permitem medir parâmetros como a direção, presença, rotação, ângulo ou corrente, para além do campo magnético, tudo isto sem qualquer contacto físico. Assim, para a maioria das aplicações, estes sensores oferecem uma medição segura, não invasiva e não destrutiva, para além de garantirem uma tecnologia confiável e de escassa manutenção. A indústria procura e exige sensores magnéticos mais pequenos, mais baratos e de baixo consumo, daí a motivação para explorar novos materiais e diferentes tecnologias, tais como os compósitos magnetoelétricos (ME) baseados em polímeros. Estes compósitos são flexíveis, versáteis, leves, de baixo custo, fáceis de se modelar em formas complexas e tipicamente envolvem um processo de fabricação a baixa temperatura, constituindo uma solução fiável e de qualidade para os sensores magnéticos. É da constatação deste potencial que surge este estudo e o objetivo desta tese: o desenvolvimento de sensores ME de base polimérica. O efeito ME é cada vez mais considerado como uma alternativa credível para a medição de campo magnético e da intensidade da corrente elétrica, podendo detetar campos magnéticos estáticos e dinâmicos. De modo a obter uma gama mais alargada de resposta ME, produziram-se nanocompósitos de Tb0.3Dy0.7Fe1.92 (Terfenol-D)/CoFe2O4/poli(fluoreto de vinilideno trifluor-etileno) (P(VDF-TrFE) e as suas propriedades morfológicas, piezoelétricas, magnéticas e magnetoelétricas foram investigadas. Os compósitos obtidos revelam uma elevada resposta piezoelétrica (≈-18 pC∙N-1) que é independente da percentagem de cada material magnetoestrictivo. Por sua vez, as propriedades magnéticas são influenciadas pela composição dos compósitos. Verificou-se que a magnetização de saturação diminuí com o aumento da percentagem de CoFe2O4 (de 18.5 para 13.3 emu∙g-1) enquanto que a magnetização e o campo coercivo aumentam (de 3.7 para 5.5 emu∙g-1 e de 355.7 para 1225.2 Oe, respetivamente) com o aumento da percentagem em massa de CoFe2O4. O efeito ME anisotrópico num compósito Fe61.6Co16.4Si10.8B11.2 (FCSB)/ poli(fluoreto de vinilideno) (PVDF)/FCSB laminado foi utilizado para desenvolver um sensor de campo magnético capaz de detetar tanto a magnitude como a direção de campos magnéticos ac e dc. A exatidão (99% para ambos os sensores ac e dc), linearidade (92% para o sensor dc e 99% para o ac), sensibilidade (15 e 1400 mV∙Oe-1 para o sensor dc e ac, respetivamente) e reprodutibilidade (99% para ambos os sensores) indicam a aptidão destes sensores para aplicações avançadas. Desenvolveu-se ainda um sensor de campo magnético dc baseado num compósito ME de PVDF/Metglas, bem como a correspondente eletrónica de leitura para processar a tensão de saída ME. O compósito ME apresenta uma ressonância eletromecânica de aproximadamente 25.4 kHz, uma resposta linear (r2=0.997) para uma gama de campos magnéticos dc entre 0–2 Oe e uma tensão de saída máxima de 112 mV (coeficiente ME α33≈30 V∙cm-1∙Oe-1). Ao incorporar um amplificador de carga, um conversor ac–rms e um microcontrolador com um conversor analógico-digital (ADC), a tensão ME não é distorcida, a linearidade manteve-se e a tensão ME aumentou para 3.3 V (α33efectivo=1000 V∙cm-1∙Oe-1). O sensor, incluindo a eletrónica de leitura, obteve um desvio máximo de 0.12 Oe com um desvio total médio de 0.04 Oe, uma sensibilidade de 1.5 V∙Oe-1 (15 kV∙T-1) e 70 nT de resolução. Tais propriedades aliadas à medida exata do campo magnético dc entre 0–2 Oe tornam este dispositivo indicado para aplicações como sensores de campo magnético terrestre, compassos digitais, navegação e detetores de anomalia no campo magnético. Foi ainda possível desenvolver e otimizar um sensor de corrente baseado num compósito ME de PVDF/Metglas, num solenoide e na correspondente eletrónica de instrumentação. A amostra ME exibe um α33 máximo de 34.48V∙cm-1∙Oe-1, uma resposta linear (r2=0.998) e uma sensibilidade de 6.7 mV∙A-1. Com a incorporação de um amplificador de carga, um conversor ac/dc de precisão e um microcontrolador, a linearidade manteve-se, a tensão ME aumentou para um máximo de 2320 mV e a sensibilidade subiu para 476.5 mV∙A-1. Estas propriedades tornam este sensor ME apropriado para a medição de corrente elétrica sem contato, para a verificação do estado de funcionamento de motores e para monitorização da condição de baterias recarregáveis, entre outros. Concluindo-se deste modo que os compósitos de ME com base em polímeros provaram ser adequados para aplicações na medição de campos magnéticos e intensidade de corrente elétrica

Towards Intelligent Tire and Self-Powered Sensing Systems

Tires are the interface between a vehicle and the ground providing forces and isolation to the vehicle. For vehicle safety, stability, maintenance, and performance, it is vital to estimate or measure tire forces, inflation pressure, and contact friction coefficient. Estimation methods can predict tire forces to some extent however; they fail in harsh maneuvers and are dependent on road surface conditions for which there is no robust estimation method. Measurement devices for tire forces exist for vehicle testing but at the cost of tens of thousands of dollars. Tire pressure-monitoring sensors (TPMS) are the only sensors available in newer and higher end vehicles to provide tire pressure, but there are no sensors to measure road surface condition or tire forces for production vehicles. With the prospect of autonomous driving on roads in near future, it is paramount to make the vehicles safe on any driving and road condition. This is only possible by additional sensors to make up for the driver’s cognitive and sensory system. Measuring road condition and tire forces especially in autonomous vehicles are vital in their safety, reliability, and public confidence in automated driving. Real time measurement of road condition and tire forces in buses and trucks can significantly improve the safety of road transportation system, and in miming/construction and off-road vehicles can improve performance, tire life and reduce operational costs. In this thesis, five different types of sensors are designed, modelled, optimized and fabricated with the objective of developing an intelligent tire. In order to design these sensors,~both electromagnetic generator (EMG) and triboelectric nanogenerators (TENG) are used. In the first two initial designed sensors, with the combination of EMG and TENG into a single package, two hybridized sensors are fabricated with promising potential for self-powered sensing. The potential of developed sensors are investigated for tire-condition monitoring system (TCMS). Considering the impressive properties of TENG units of the developed hybridized devices, three different flexible nanogenerators, only based on this newly developed technology, are developed for TCMS. The design, modelling, working mechanism, fabrication procedure, and experimental results of these TENG sensors are fully presented for applications in TCMS. Among these three fabricated sensors, one of them shows an excellent capability for TCMS because of its high flexibility, stable and high electrical output,and an encapsulated structure. The high flexibility of developed TENG sensor is a very appealing feature for TCMS, which cannot be found in any available commercial sensor. The fabricated TENG sensors are used for developing an intelligent tire module to be eventually used for road testing. Several laboratory and road tests are performed to study the capability of this newly developed TENG-based sensor for tire-condition monitoring system. However the development of this sensor is in its early stage, it shows a promising potential for installation into the hostile environment of tires and measuring tire-road interacting forces. A comparative studies are provided with respect to Michigan Scientific transducer to investigate the potential of this flexible nanogenerator for TCMS. It is worth mentioning that this PhD thesis presents one of the earliest works on the application of TENG-based sensor for a real-life system. Also, the potential of commercially available thermally and mechanically durable Micro Fiber Composite (MFC) sensor is experimentally investigated for TCMS with fabricating another set of intelligent tire. Several testing scenarios are performed to examine the potential of these sensors for TCMS taking into account a simultaneous measurement from Michigan Scientific transducer. Although both flexibility and the cost of this sensor is not comparable with the fabricated TENG device, they have shown a considerable and reliable performance for online measuring of tire dynamical parameters in different testing scenarios, as they can be used for both energy harvesting and sensing application in TCMS. The extensive road testing results based on the MFC sensors provide a valuable set of data for future research in TCMS. It is experimentally shown that MFC sensor can generate up to 1.4 $\mu W$ electrical power at the speed of 28 $[kph]$. This electrical output shows the high capability of this sensor for self-powered sensing application in TCMS. Results of this thesis can be used as a framework by researchers towards self-powered sensing system for real-world applications such as intelligent tires

Augmenting Percussion with Electronics in Improvised Music Performance

This commentary augments audio and video recordings that should be considered the essence of the study. The sound recordings comprise an original body of work that resulted from my interest in extending the possibilities of a standard drum set by augmenting it with electronics. It developed from an early interest in analogue, electroacoustic devices – such as the Dexion frames used by Tony Oxley and Paul Lytton to an engagement with digital electronics, specifically Max MSP, that was unknown to me at the outset of the study. The digital tools caused me to re-evaluate my thinking; to go beyond extending the sound-world at my disposal to engage with and consider artificial intelligence and the potential of creating a surrogate, software improviser with a degree of agency that challenged my thinking about human-computer interaction and confounded the issue of whether I was playing in a solo or duo setting. The commentary demonstrates the centrality of free improvisation to my approach and the recordings document my use of technologies, varying from the seemingly primitive (wooden beaters) to the apparently sophisticated (Max MSP) where I fully explore the affordances of each encounter